EXHIBIT 21.0

Subsidiaries of the Company

The following are the Company’s subsidiaries as of the close of the fiscal year ended June 30, 2026. All beneficial interests are wholly-owned, directly or indirectly, by the Company and are included in the Company’s consolidated financial statements.

Ayman Island

Name

  ​ ​ ​

State or Jurisdiction of Organization

Alarm Lock Systems, LLC

Delaware

Continental Instruments, LLC

New York

Marks USA I LLC

New York

Napco Americas

Cayman Islands

Napco DR, S.A.S.

Dominican Republic

Napco Technologies International, Inc.

Delaware

Video Alert, LLC

New York

E-18