Pursuant to the offer of Transom Axis MergerSub, Inc. (“Purchaser”) to purchase all outstanding Shares of SGMA, the undersigned encloses herewith and surrenders the following certificate(s) representing Shares of SGMA:

THE INSTRUCTIONS ACCOMPANYING THIS LETTER OF TRANSMITTAL SHOULD BE READ CAREFULLY BEFORE THIS LETTER OF TRANSMITTAL IS COMPLETED.

DELIVERY OF THIS LETTER OF TRANSMITTAL TO AN ADDRESS OTHER THAN AS SET FORTH ABOVE FOR THE DEPOSITARY WILL NOT CONSTITUTE VALID DELIVERY. YOU MUST SIGN THIS LETTER OF TRANSMITTAL IN THE APPROPRIATE SPACE PROVIDED BELOW, WITH A SIGNATURE GUARANTEE, IF REQUIRED, AND COMPLETE THE IRS FORM W-9 SET FORTH BELOW, IF REQUIRED. PLEASE READ THE INSTRUCTIONS ACCOMPANYING THIS LETTER OF TRANSMITTAL CAREFULLY BEFORE COMPLETING THIS LETTER OF TRANSMITTAL.

ALL QUESTIONS REGARDING THE OFFER SHOULD BE DIRECTED TO THE INFORMATION AGENT, D.F. KING & CO., INC., AT 1-877-732-3613 OR AT THE ADDRESS SET FORTH ON THE BACK PAGE OF THIS LETTER OF TRANSMITTAL.

IF YOU WOULD LIKE ADDITIONAL COPIES OF THIS LETTER OF TRANSMITTAL OR ANY OF THE OTHER MATERIALS RELATED TO THE OFFER, YOU SHOULD CONTACT THE INFORMATION AGENT, D.F. KING & CO., INC., AT 1-877-732-3613.

THE OFFER IS NOT BEING MADE TO (NOR WILL TENDERS BE ACCEPTED FROM OR ON BEHALF OF) THE HOLDERS OF SHARES IN ANY JURISDICTION IN WHICH THE MAKING OF THE OFFER OR ACCEPTANCE THEREOF WOULD NOT BE IN COMPLIANCE WITH THE LAWS OF SUCH JURISDICTION. IN THOSE JURISDICTIONS WHERE APPLICABLE LAWS OR REGULATIONS REQUIRE THE OFFER TO BE MADE BY A LICENSED BROKER OR DEALER, THE OFFER SHALL BE DEEMED TO BE MADE ON BEHALF OF MERGER SUB (AS DEFINED BELOW) BY ONE OR MORE REGISTERED BROKERS OR DEALERS LICENSED UNDER THE LAWS OF SUCH JURISDICTION TO BE DESIGNATED BY MERGER SUB.

This Letter of Transmittal is being delivered to you in connection with the offer by Transom Axis MergerSub, Inc., a Delaware corporation (“Merger Sub”), and a wholly owned subsidiary of Transom Axis AcquireCo, LLC, a Delaware limited liability company (“Parent”), to purchase all of the issued and outstanding shares of common stock, par value $0.01 per share (the “Shares”), of SigmaTron International, Inc., a Delaware corporation (“SigmaTron”), at a purchase price of $3.02 per Share (the “Offer Price”), net to the stockholder in cash, without interest and less any required tax withholding, upon the terms and subject to the conditions set forth in this Letter of Transmittal and in the related Offer to Purchase, dated June 26, 2025 (the “Offer to Purchase,” which, together with this Letter of Transmittal, as each may be amended or supplemented from time to time, collectively constitute the “Offer”).

The Offer expires at the Expiration Date. The term “Expiration Date” means one minute past 11:59 p.m., Eastern Time, on July 24, 2025, unless the expiration of the Offer is extended to a subsequent date in accordance with the terms of the Agreement and Plan of Merger, dated May 20, 2025 (as it may be amended from time to time, the “Merger Agreement”), in which case the term “Expiration Date” means such subsequent time on such subsequent date.

You should use this Letter of Transmittal if you are tendering Shares represented by stock certificates or held in book-entry form on the books of SigmaTron’s stock transfer agent, Equiniti Trust Company, LLC (in such capacity, the “Transfer Agent”), or if the Shares are being tendered pursuant to the procedures for book-entry transfer as set forth in Section 3 of the Offer to Purchase or through The Depository Trust Company’s (“DTC”) Automated Tender Offer Program (“ATOP”) unless, in the case of Shares held or transferred in book-entry form or through ATOP, an Agent’s Message (as defined below) is being delivered to Equiniti Trust Company, LLC, the depositary and paying agent for the Offer (in such capacity, the “Depositary”) in lieu of this Letter of Transmittal. Delivery of documents to DTC will not constitute delivery to the Depositary.

If any certificate representing any Shares you are tendering with this Letter of Transmittal has been lost, stolen or destroyed, you should contact the Transfer Agent by phone at 1-877-248-6417 OR 1-718-921-8317 (toll free in the United States) regarding the requirements for replacement. You may be required to post a bond to secure against the risk that such certificates may be subsequently recirculated. You are urged to contact the Transfer Agent immediately in order to receive further instructions, for a determination of whether you will need to post a bond and to permit timely processing of this documentation. See Instruction 10.

IF TENDERED SHARES ARE BEING DELIVERED BY BOOK-ENTRY TRANSFER TO THE ACCOUNT MAINTAINED BY THE DEPOSITARY WITH DTC, COMPLETE THE FOLLOWING (ONLY FINANCIAL INSTITUTIONS THAT ARE PARTICIPANTS IN DTC MAY DELIVER SHARES BY BOOK-ENTRY TRANSFER):

The undersigned hereby tenders to Transom Axis MergerSub, Inc., a Delaware corporation (“Merger Sub”) and a wholly owned subsidiary of Transom Axis AcquireCo, LLC, a Delaware limited liability company (“Parent”), the above-described shares of common stock, par value $0.01 per share (the “Shares”), of SigmaTron International, Inc., a Delaware corporation (“SigmaTron”), at a purchase price of $3.02 per Share (the “Offer Price”), net to the stockholder in cash, without interest and less any required tax withholding, upon the terms and subject to the conditions set forth in the Offer to Purchase, dated June 26, 2025, which the undersigned hereby acknowledges the undersigned has received (the “Offer to Purchase,” which, together with this Letter of Transmittal, as each may be amended or supplemented from time to time, collectively constitute the “Offer”).

The Offer expires at the Expiration Date. The term “Expiration Date” means one minute past 11:59 P.M., Eastern Time, on July 24, 2025, unless the expiration of the Offer is extended to a subsequent date in accordance with the terms of the Merger Agreement, in which case the term “Expiration Date” means such subsequent time on such subsequent date.

The undersigned hereby acknowledges that Merger Sub reserves the right to transfer or assign, from time to time, in whole or in part, to one or more of its direct or indirect wholly owned subsidiaries of Parent, without the consent of SigmaTron, the right to purchase the Shares tendered herewith.

Upon the terms and subject to the conditions of the Offer (including, if the Offer is extended or amended, the terms and conditions of such extension or amendment), subject to, and effective upon, acceptance for payment of the Shares validly tendered herewith and not properly withdrawn prior to the Expiration Date in accordance with the terms of the Offer, the undersigned hereby sells, assigns and transfers to, or upon the order of, Merger Sub, all right, title and interest in and to all of the Shares being tendered hereby and any and all dividends, distributions, rights, other Shares or other securities issued or issuable in respect of such Shares on or after the date hereof (collectively, “Distributions”). In addition, subject to, and effective upon, acceptance for payment of the Shares validly tendered herewith and not properly withdrawn prior to the Expiration Date in accordance with the terms of the Offer, the undersigned hereby irrevocably appoints each of the designees of Merger Sub as the attorneys-in-fact and proxies of the undersigned with respect to such Shares and any and all Distributions, with full power of substitution (such proxies and power of attorney being deemed to be an irrevocable power coupled with an interest in the tendered Shares and any Distributions), to the full extent of such stockholder’s rights with respect to such Shares and any Distributions (a) to deliver certificates representing such Shares (the “Share Certificates”) and any and all Distributions, or transfer of ownership of such Shares and any and all Distributions on the account books maintained by The Depository Trust Company (“DTC”), together, in either such case, with all accompanying evidence of transfer and authenticity, to or upon the order of Merger Sub, (b) to present such Shares and any and all Distributions for transfer on the books of SigmaTron, and (c) to receive all benefits and otherwise exercise all rights of beneficial ownership of such Shares and any Distributions, all upon the terms and subject to the conditions of the Offer.

By executing this Letter of Transmittal (or taking action resulting in the delivery of an Agent’s Message (as defined below)), the undersigned hereby irrevocably appoints each of the designees of Merger Sub as the attorneys-in-fact and proxies of the undersigned, each with full power of substitution, to the full extent of such stockholder’s rights with respect to the Shares tendered hereby and not properly withdrawn that have been accepted for payment by Merger Sub and with respect to any and all Distributions. The designees of Merger Sub will, with respect to such Shares and Distributions, be empowered to exercise all voting and any other rights of such stockholder, as they, in their sole discretion, may deem proper at any annual, special, adjourned or postponed meeting of SigmaTron’s stockholders, by written consent in lieu of any such meeting or otherwise as they, in their sole discretion, deem proper with respect to all Shares and any and all Distributions. This proxy and power of attorney shall be irrevocable and coupled with an interest in the tendered Shares and any and all Distributions. Such appointment is effective when, and only to the extent that, Merger Sub accepts the Shares tendered with this Letter of Transmittal for payment pursuant to the Offer. Upon the effectiveness of such appointment, without further action, all prior powers of attorney, proxies and consents given by the undersigned with respect to such Shares and any and all associated Distributions (other than prior powers of attorney, proxies or consent given by the undersigned to Merger Sub or SigmaTron) will be revoked, and no subsequent powers of attorney, proxies, consents or revocations (other than powers of attorney, proxies, consents or revocations given to Merger Sub or SigmaTron) may be given (and, if given, will not be deemed effective).

Merger Sub reserves the right to require that, in order for Shares to be deemed validly tendered, immediately upon Merger Sub’s acceptance for payment of such Shares, Merger Sub must be able to exercise full voting, consent and other rights with respect to such Shares and other related securities or rights, including voting at any meeting of stockholders of SigmaTron or executing a written consent concerning any matter.

The undersigned hereby represents and warrants that the undersigned has full power and authority to tender, sell, assign and transfer any and all of the Shares tendered hereby and any and all Distributions and, when the same are accepted for payment by Merger Sub, Merger Sub will acquire good, marketable and unencumbered title thereto, free and clear of all liens, restrictions, charges and encumbrances, and that the same will not be subject to any adverse claims. The undersigned hereby represents and warrants that the undersigned is the holder of record of the Shares, or the Share Certificate(s) have been endorsed to the undersigned in blank, or the undersigned is a participant in DTC whose name appears on a security position listing as the owner of the Shares. The undersigned will, upon request, execute and deliver any additional documents deemed by Equiniti Trust Company, LLC, the depositary and paying agent for the Offer (the “Depositary”) or Merger Sub to be necessary or desirable to complete the sale, assignment and transfer of any and all of the Shares tendered hereby and any and all Distributions. In addition, the undersigned shall promptly remit and transfer to the Depositary for the account of Merger Sub any and all Distributions in respect of any and all of the Shares tendered hereby, accompanied by appropriate documentation of transfer and, pending such remittance and transfer or appropriate assurance thereof, Merger Sub shall be entitled to all rights and privileges as owner of any such Distributions and may withhold the entire Offer Price or deduct from such Offer Price the amount or value thereof, as determined by Merger Sub in its sole discretion.

It is understood that the undersigned will not receive payment for the Shares unless and until the Shares are accepted for payment and until the Share Certificate(s) owned by the undersigned are timely received by the Depositary at the address set forth above, together with such additional documents as the Depositary may require, or, in the case of Shares held in book-entry form, ownership of Shares is validly and timely transferred on the account books maintained by DTC, and until the same are processed for payment by the Depositary.

IT IS UNDERSTOOD THAT THE METHOD OF DELIVERY OF THE SHARES, THE SHARE CERTIFICATE(S) AND ALL OTHER REQUIRED DOCUMENTS (INCLUDING DELIVERY THROUGH DTC) IS AT THE ELECTION AND RISK OF THE UNDERSIGNED AND THAT THE RISK OF LOSS OF SUCH SHARES, SHARE CERTIFICATE(S) AND OTHER DOCUMENTS SHALL PASS ONLY AFTER THE DEPOSITARY HAS ACTUALLY RECEIVED THE SHARES OR SHARE CERTIFICATE(S) (INCLUDING, IN THE CASE OF A BOOK-ENTRY TRANSFER, BY BOOK-ENTRY CONFIRMATION (AS DEFINED BELOW)). IF DELIVERY IS BY MAIL, IT IS RECOMMENDED THAT ALL SUCH DOCUMENTS BE SENT BY PROPERLY INSURED REGISTERED MAIL WITH RETURN RECEIPT REQUESTED. IN ALL CASES, SUFFICIENT TIME SHOULD BE ALLOWED TO ENSURE TIMELY DELIVERY PRIOR TO THE EXPIRATION DATE.

All authority conferred or agreed to be conferred pursuant to this Letter of Transmittal shall not be affected by, and shall survive, the death or incapacity of the undersigned and any obligation of the undersigned hereunder shall be binding upon the heirs, executors, administrators, trustees in bankruptcy, personal representatives, successors and assigns of the undersigned. Except upon the terms and subject to the conditions of the Offer, a tender pursuant to this Letter of Transmittal is irrevocable.

The undersigned understands that the acceptance for payment by Merger Sub of Shares tendered pursuant to one of the procedures described in Section 3 of the Offer to Purchase and in the instructions hereto will constitute a binding agreement between the undersigned and Merger Sub upon the terms and subject to the conditions of the Offer. The undersigned recognizes that under certain circumstances, upon the terms and subject to the conditions of the Offer, Merger Sub may not be required to accept for payment any of the Shares tendered hereby. Without limiting the foregoing, if the Offer Price is amended in accordance with the terms of the Merger Agreement, the price to be paid to the undersigned will be the amended price notwithstanding the fact that a different price is stated in this Letter of Transmittal.

Unless otherwise indicated herein under “Special Payment Instructions,” please issue the check for the Offer Price in the name(s) of, and/or return any Share Certificates representing Shares not validly tendered or accepted for payment to, the holder(s) of record appearing under “Description of Shares Tendered.” Similarly, unless otherwise indicated under “Special Delivery Instructions,” please mail the check for the Offer Price and/or return any Share Certificates representing Shares not validly tendered or accepted for payment (and accompanying documents, as appropriate) to the address(es) of the holder(s) of record appearing under “Description of Shares Tendered.” The undersigned recognizes that Merger Sub has no obligation, pursuant to the Special Payment Instructions, to transfer any Shares from the name(s) of the registered holder(s) thereof if Merger Sub does not accept for payment any of the Shares so tendered.

In the event that both the Special Delivery Instructions and the Special Payment Instructions are completed, please issue the check for the Offer Price and/or issue any Share Certificates representing Shares not validly tendered or accepted for payment (and any accompanying documents, as appropriate) in the name of, and deliver such check and/or return such Share Certificates (and any accompanying documents, as appropriate) to, the person or persons so indicated. Unless otherwise indicated herein in the box titled “Special Payment Instructions,” please credit any Shares validly tendered hereby or by an Agent’s Message and delivered by book-entry transfer, but which are not purchased, by crediting the account at DTC designated above. The undersigned recognizes that Merger Sub has no obligation pursuant to the Special Payment Instructions to transfer any Shares from the name of the holder of record thereof if Merger Sub does not accept for payment any of the Shares so validly tendered.

(Must be signed by holder(s) of record exactly as name(s) appear(s) on Share Certificate(s) or on a security position listing or by person(s) authorized to become holder(s) of record by certificates and documents transmitted herewith. If signature is by trustees, executors, administrators, guardians, attorneys-in-fact, officers of corporations or others acting in a fiduciary or representative capacity, please set forth full title and see Instruction 5. For information concerning signature guarantees, see Instruction 1.)

1. Guarantee of Signatures for Shares. No signature guarantee is required on this Letter of Transmittal (a) if this Letter of Transmittal is signed by the holder(s) of record (which term, for purposes of this Section 1, includes any participant in DTC’s systems whose name appears on a security position listing as the owner of the Shares) of the Shares tendered therewith, unless such holder or holders have completed either the box entitled “Special Delivery Instructions” or the box entitled “Special Payment Instructions” on this Letter of Transmittal or (b) if the Shares are tendered for the account of a financial institution (including most commercial banks, savings and loan associations and brokerage houses) that is a member in good standing of the Security Transfer Agents Medallion Program or any other “eligible guarantor institution,” as such term is defined in Rule 17Ad-15 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) (each, an “Eligible Institution” and collectively, “Eligible Institutions”) (for example, the Securities Transfer Agents Medallion Program®, the New York Stock Exchange Inc. Medallion Signature ProgramSM and the Stock Exchanges Medallion Program®). In all other cases, all signatures on this Letter of Transmittal must be guaranteed by an Eligible Institution. See Instruction 5.

2. Delivery of Letter of Transmittal and Share Certificates or Book-Entry Confirmations. This Letter of Transmittal is to be completed by stockholders that are tendering Shares represented by Share Certificates or held in book-entry form on the books of the Transfer Agent, or if the Shares are being tendered pursuant to the procedures for book-entry transfer as set forth in Section 3 of the Offer to Purchase or through ATOP unless, in the case of Shares held or transferred in book-entry form or through ATOP, an Agent’s Message is being delivered to the Depositary in lieu of this Letter of Transmittal. Payment for Shares accepted for payment pursuant to the Offer will in all cases only be made after timely receipt by the Depositary of (i) to the extent the Shares are not already held with the Depositary, Share Certificates or a Book-Entry Confirmation (as defined in the Offer to Purchase) of a book-entry transfer of such Shares into the Depositary’s account at DTC pursuant to the procedures set forth in Section 3 of the Offer to Purchase, (ii) this Letter of Transmittal, properly completed and duly executed, with any required signature guarantees (or, in the case of a book-entry transfer or a tender through DTC’s ATOP, an Agent’s Message in lieu of this Letter of Transmittal) and (iii) any other documents required by this Letter of Transmittal or the Depositary, in each case prior to the Expiration Date.

The term “Agent’s Message” means a message transmitted through electronic means by DTC in accordance with the normal procedures of DTC to, and received by, the Depositary and forming part of a Book-Entry Confirmation, that states that DTC has received an express acknowledgment from the participant in DTC tendering the Shares that are the subject of such Book-Entry Confirmation that such participant has received and agrees to be bound by the terms of, this Letter of Transmittal, and that Merger Sub may enforce such agreement against such participant. The term “Agent’s Message” also includes any hard copy printout evidencing such message generated by a computer terminal maintained at the Depositary’s office.

THE METHOD OF DELIVERY OF THE SHARES (OR SHARE CERTIFICATES), THIS LETTER OF TRANSMITTAL AND ALL OTHER REQUIRED DOCUMENTS, INCLUDING DELIVERY THROUGH DTC, IS AT THE ELECTION AND RISK OF THE TENDERING STOCKHOLDER. DELIVERY OF THE SHARES (OR SHARE CERTIFICATES), THIS LETTER OF TRANSMITTAL AND ALL OTHER REQUIRED DOCUMENTS WILL BE DEEMED MADE, AND RISK OF LOSS THEREOF SHALL PASS, ONLY WHEN THEY ARE ACTUALLY RECEIVED BY THE DEPOSITARY (INCLUDING, IN THE CASE OF A BOOK-ENTRY TRANSFER OF SHARES, BY BOOK-ENTRY CONFIRMATION WITH RESPECT TO SUCH SHARES). IF SUCH DELIVERY IS BY MAIL, IT IS RECOMMENDED THAT THE SHARES (OR SHARE CERTIFICATES), THIS LETTER OF TRANSMITTAL AND ALL OTHER REQUIRED DOCUMENTS BE SENT BY PROPERLY INSURED REGISTERED MAIL WITH RETURN RECEIPT REQUESTED. IN ALL CASES, SUFFICIENT TIME SHOULD BE ALLOWED TO ENSURE TIMELY DELIVERY PRIOR TO THE EXPIRATION DATE.

No alternative, conditional or contingent tenders will be accepted and no fractional Shares will be purchased. All tendering stockholders, by execution of this Letter of Transmittal, waive any right to receive any notice of the acceptance of their Shares for payment.

3. Inadequate Space. If the space provided on the cover page to this Letter of Transmittal is inadequate, the certificate numbers and/or the number of Shares should be listed on a separate schedule attached hereto and separately signed on each page thereof in the same manner as this Letter of Transmittal is signed.

4. Partial Tenders (Applicable to Certificate Stockholders Only). If fewer than all the Shares evidenced by any Share Certificate delivered to the Depositary are to be tendered, stockholders should contact the Transfer Agent by phone at 1-877-248-6417 OR 1-718-921-8317 (toll free in the United States) to arrange to have such Share Certificate divided into separate Share Certificates representing the number of shares to be tendered and the number of shares to not be tendered. The stockholder should then tender the Share Certificate representing the number of Shares to be tendered as set forth in this Letter of Transmittal. All Shares represented by Share Certificates delivered to the Depositary will be deemed to have been tendered.

5. Signatures on Letter of Transmittal; Stock Powers and Endorsements. If this Letter of Transmittal is signed by the holder(s) of record of the Shares tendered hereby, the signature(s) must correspond with the name(s) as written on the face of the Share Certificate(s) without alteration or any other change whatsoever.

If any Shares tendered hereby are owned of record by two or more joint owners, all such owners must sign this Letter of Transmittal.

If any tendered Shares are registered in the names of different holder(s), it will be necessary to complete, sign and submit as many separate Letters of Transmittal as there are different registrations of such Shares.

If this Letter of Transmittal or any certificates or stock powers are signed by trustees, executors, administrators, guardians, attorneys-in-fact, officers of corporations or others acting in a fiduciary or representative capacity, such persons should so indicate when signing, and proper evidence satisfactory to Merger Sub of their authority so to act must be submitted with this Letter of Transmittal.

If this Letter of Transmittal is signed by the holder(s) of record of the Shares listed and transmitted hereby, no endorsements of Share Certificates or separate stock powers are required unless payment is to be made to, or Share Certificates representing Shares not tendered or accepted for payment are to be issued in the name of, a person other than the holder(s) of record, in which case the Share Certificates representing the Shares tendered by this Letter of Transmittal must be endorsed or accompanied by appropriate stock powers, in either case, signed exactly as the name(s) of the holder(s) of record appear(s) on the Share Certificates. Signatures on such Share Certificates or stock powers must be guaranteed by an Eligible Institution.

If this Letter of Transmittal is signed by a person other than the holder(s) of record of the Share(s) listed, the Share Certificate(s) must be endorsed or accompanied by the appropriate stock powers, in either case, signed exactly as the name or names of the holder(s) of record appear(s) on the Share Certificate(s). Signatures on such Share Certificates or stock powers must be guaranteed by an Eligible Institution.

6. Transfer Taxes. Except as otherwise provided in this Instruction 6, all transfer taxes with respect to the transfer and sale of Shares contemplated hereby shall be paid or caused to be paid by Merger Sub. If payment of the Offer Price is to be made to, or (in the circumstances permitted hereby) if Share Certificates not validly tendered or accepted for payment are to be registered in the name of, any person other than the holder(s) of record or if tendered Share Certificates are registered in the name of any person other than the person signing this Letter of Transmittal, the amount of any transfer taxes (whether imposed on the holder(s) of record or such person) payable on account of the transfer to such person, will need to be paid by such holder unless such holder establishes to the satisfaction of Parent that such transfer taxes have been paid or are not required to be paid.

7. Special Payment and Delivery Instructions. If a check for the Offer Price is to be issued, and/or Share Certificates representing Shares not validly tendered or accepted for payment are to be issued or returned to, a person other than the signer(s) of this Letter of Transmittal or to an address other than that shown in the box titled “Description of Shares Tendered” above, the appropriate boxes on this Letter of Transmittal should be completed.

8. Requests for Assistance or Additional Copies. Questions or requests for assistance may be directed to D.F. King & Co., Inc.(the “Information Agent”) at its address and telephone number set forth below. Additional copies of the Offer to Purchase, this Letter of Transmittal and other materials related to the Offer may be obtained at no cost to stockholders from the Information Agent. Additionally, copies of the Offer to Purchase, this Letter of Transmittal and any other materials related to the Offer are available free of charge at www.sec.gov. Stockholders may also contact their brokers, dealers, commercial banks, trust companies or other nominees for assistance.

9. U.S. Federal Backup Withholding. Under U.S. federal income tax laws, the Depositary will be required to withhold a portion of the amount of any payments made to certain stockholders (or other payees) pursuant to the Offer, as applicable. To avoid such backup withholding, each tendering stockholder (or other payee) that is or is treated as a United States person (for U.S. federal income tax purposes) and that does not otherwise establish an exemption from U.S. federal backup withholding should complete and return the attached Internal Revenue Service (“IRS”) Form W-9, certifying that such stockholder (or other payee) is a United States person, that the taxpayer identification number (“TIN”) provided is correct, and that such stockholder (or other payee) is not subject to backup withholding.

Certain stockholders and other payees (including, among others, corporations, non-resident foreign individuals and foreign entities) are not subject to these backup withholding and reporting requirements. Exempt United States persons should indicate their exempt status on IRS Form W-9. A tendering stockholder (or other payee) who is a foreign individual or a foreign entity should complete, sign, and submit to the Depositary the appropriate IRS Form W-8. The appropriate IRS Form W-8 may be downloaded from the Internal Revenue Service’s website at the following address: www.irs.gov. Failure to complete the IRS Form W-9 or the appropriate IRS Form W-8 will not, by itself, cause Shares to be deemed invalidly tendered, but may require the Depositary to withhold a portion of the amount of any payments made of the Offer Price pursuant to the Offer.

Tendering stockholders (or other payees) should consult their tax advisors as to any qualification for exemption from backup withholding, and the procedure for obtaining the exemption.

NOTE: FAILURE TO COMPLETE AND RETURN THE IRS FORM W-9 (OR APPROPRIATE IRS FORM W-8, AS APPLICABLE) MAY RESULT IN BACKUP WITHHOLDING OF A PORTION OF ANY PAYMENTS MADE TO YOU PURSUANT TO THE OFFER. PLEASE REVIEW THE “IMPORTANT U.S. TAX INFORMATION” SECTION BELOW.

10. Lost, Stolen or Destroyed Share Certificates. In the event that any Share Certificate has been lost, stolen or destroyed, upon the holder’s delivery of an affidavit of loss to the Depositary (and, if required by Parent or the Depositary, the posting by such holder of a bond in customary amount and upon such terms as may be reasonably required by Parent or the Depositary as indemnity against any claim that may be made against it or SigmaTron with respect to such Share Certificate), Parent shall cause the Depositary to deliver as consideration for the lost, stolen or destroyed Share Certificate the applicable right to receive the Offer Price from Merger Sub payable in respect of the Shares represented by such Share Certificate, without interest and less any required tax withholding. This Letter of Transmittal and related documents cannot be processed until the procedures for replacing lost, stolen or destroyed Share Certificates have been followed.

Waiver of Conditions. Merger Sub expressly reserves the right to waive, at any time and to the extent permitted by applicable law, in whole or in part, any Offer Condition (as defined in the Offer to Purchase) or modify the terms of the Offer, in any manner not inconsistent with the Merger Agreement, except that SigmaTron’s prior written approval is required for Merger Sub to, and for Parent to permit Merger Sub to:

11. Determination of Validity. All questions as to the validity, form, eligibility (including time of receipt) and acceptance for payment of any tender of Shares will be determined by Merger Sub, in Merger Sub’s sole discretion, which determination will be final and binding on all parties, subject to the rights of holders of Shares to challenge such determination with respect to their Shares in a court of competent jurisdiction and any subsequent judgment of any such court. Merger Sub reserves the absolute right to reject any and all tenders determined by Merger Sub not to be in proper form or the acceptance for payment of which may, in Merger Sub’s opinion, be unlawful. Merger Sub also reserves the absolute right to waive any defect or irregularity in the tender of any Shares of any particular stockholder, whether or not similar defects or irregularities are waived in the case of other stockholders. No tender of Shares will be deemed to have been validly made until all defects and irregularities have been cured or waived to Merger Sub’s satisfaction. None of Merger Sub, Parent or any of their respective affiliates or assigns, the Depositary, the Information Agent or any other person will be under any duty to give any notification of any defects or irregularities in tenders or incur any liability for failure to give any such notification. Subject to the terms of the Merger Agreement and the rights of holders of Shares to challenge any interpretation with respect to their Shares in a court of competent jurisdiction and any subsequent judgment of any such court, Merger Sub’s interpretation of the terms and conditions of the Offer (including this Letter of Transmittal and the instructions hereto) will be final and binding.

IMPORTANT: THIS LETTER OF TRANSMITTAL OR AN AGENT’S MESSAGE, TOGETHER WITH SHARE CERTIFICATE(S) OR BOOK-ENTRY CONFIRMATION AND ALL OTHER REQUIRED DOCUMENTS, MUST BE RECEIVED BY THE DEPOSITARY PRIOR TO THE EXPIRATION DATE.

Under U.S. federal income tax law, a stockholder (or other payee) whose tendered Shares are accepted for payment is required by law to provide the Depositary (as payer) with such stockholder’s (or other payee’s) properly certified TIN and certain other information on an IRS Form W-9 or otherwise establish a basis for exemption from backup withholding (including by providing a properly completed and correct applicable IRS Form W-8). If such stockholder (or other payee) is a U.S. individual, the TIN is such stockholder’s (or other payee’s) social security number. If the Depositary is not provided with the correct TIN in the required manner or the stockholder (or other payee) does not otherwise establish its exemption from backup withholding (as described below), payments that are made to such stockholder (or other payee) with respect to Shares purchased pursuant to the Offer may be subject to backup withholding.

If backup withholding of U.S. federal income tax on payments for Shares made in the Offer or under the Merger Agreement applies, the Depositary is required to withhold 24% of any payments of the Offer Price made to the stockholder (or other payee). Backup withholding is not an additional tax. Rather, the U.S. federal income tax liability of persons subject to backup withholding will be reduced by the amount of tax withheld. If withholding results in an overpayment of taxes, a refund or credit may be obtained from the IRS provided that the required information is timely furnished to the IRS.

Certain stockholders and other payees (including, among others, corporations, non-resident foreign individuals and foreign entities) are not subject to these backup withholding and reporting requirements. An exempt stockholder (or other exempt payee) that is a United States person should indicate its exempt status on IRS Form W-9, in accordance with the instructions thereto. A stockholder (or other payee) who is a foreign individual or a foreign entity should complete, sign, and submit to the Depositary the appropriate IRS Form W-8. The appropriate IRS Form W-8 may be downloaded from the IRS’s website at the following address: www.irs.gov.

Please consult your tax advisor for further guidance regarding the completion of the IRS Form W-9, IRS Form W-8BEN or W-8BEN-E (or other applicable IRS Form W-8) to claim exemption from backup withholding. Failure to complete the IRS Form W-9 will not, by itself, cause Shares to be deemed invalidly tendered, but may require the Depositary to withhold a portion of the amount of any payments of the Offer Price pursuant to the Offer.

Method of delivery of the certificate(s) is at the option and risk of the owner thereof. See Instruction 2. Mail or deliver this Letter of Transmittal, together with the certificate(s) representing your shares, to:

DELIVERY OF THIS LETTER OF TRANSMITTAL TO AN ADDRESS OTHER THAN AS SET FORTH ABOVE WILL NOT CONSTITUTE A VALID DELIVERY TO THE DEPOSITARY.

Questions or requests for assistance may be directed to the Information Agent at the address and telephone number listed below. Additional copies of the Offer to Purchase, this Letter of Transmittal and other materials related to the Offer may be obtained at no cost to stockholders from the Information Agent. Additionally, copies of the Offer to Purchase, this Letter of Transmittal and any other materials related to the Offer are available free of charge at www.sec.gov. Stockholders may also contact their brokers, dealers, commercial banks, trust companies or other nominees for assistance.