Shareholder Report

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® US Quality Low Volatility Index Fund	$4	0.08%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$169,594,931
Number of Portfolio Holdings	118
Portfolio Turnover Rate	23%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® Developed Markets ex-US Quality Low Volatility Index Fund	$6	0.12%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$53,245,173
Number of Portfolio Holdings	188
Portfolio Turnover Rate	23%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® Emerging Markets Quality Low Volatility Index Fund	$10	0.18%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$15,948,107
Number of Portfolio Holdings	155
Portfolio Turnover Rate	24%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® Morningstar US Market Factor Tilt Index Fund	$13	0.25%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$2,113,735,443
Number of Portfolio Holdings	1,966
Portfolio Turnover Rate	8%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® Morningstar Developed Markets ex-US Factor Tilt Index Fund	$21	0.39%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$633,604,041
Number of Portfolio Holdings	2,354
Portfolio Turnover Rate	10%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® Morningstar Emerging Markets Factor Tilt Index Fund	$31	0.57%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$347,037,066
Number of Portfolio Holdings	3,068
Portfolio Turnover Rate	14%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® US Quality Large Cap Index Fund	$13	0.25%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$902,725,215
Number of Portfolio Holdings	178
Portfolio Turnover Rate	10%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® STOXX^® US ESG Select Index Fund	$17	0.32%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$128,251,165
Number of Portfolio Holdings	253
Portfolio Turnover Rate	17%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® STOXX^® Global ESG Select Index Fund	$22	0.42%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$108,478,325
Number of Portfolio Holdings	707
Portfolio Turnover Rate	19%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® ESG & Climate US Large Cap Core Index Fund	$5	0.09%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$110,667,930
Number of Portfolio Holdings	171
Portfolio Turnover Rate	19%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® ESG & Climate Developed Markets ex-US Core Index Fund	$6	0.12%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$78,678,965
Number of Portfolio Holdings	236
Portfolio Turnover Rate	11%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® Morningstar Global Upstream Natural Resources Index Fund	$26	0.46%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$7,493,670,646
Number of Portfolio Holdings	167
Portfolio Turnover Rate	14%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® STOXX^® Global Broad Infrastructure Index Fund	$25	0.47%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$3,065,476,780
Number of Portfolio Holdings	198
Portfolio Turnover Rate	7%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® Global Quality Real Estate Index Fund	$24	0.45%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$386,208,767
Number of Portfolio Holdings	156
Portfolio Turnover Rate	20%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® Quality Dividend Index Fund	$19	0.37%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$2,126,669,391
Number of Portfolio Holdings	144
Portfolio Turnover Rate	13%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® Quality Dividend Defensive Index Fund	$19	0.37%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$530,297,082
Number of Portfolio Holdings	138
Portfolio Turnover Rate	11%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® International Quality Dividend Index Fund	$25	0.47%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$1,097,265,554
Number of Portfolio Holdings	210
Portfolio Turnover Rate	27%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® International Quality Dividend Dynamic Index Fund	$26	0.47%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$101,546,015
Number of Portfolio Holdings	212
Portfolio Turnover Rate	30%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® iBoxx^® 3-Year Target Duration TIPS Index Fund	$9	0.18%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$2,584,501,347
Number of Portfolio Holdings	22
Portfolio Turnover Rate	39%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® iBoxx^® 5-Year Target Duration TIPS Index Fund	$9	0.18%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$1,027,952,231
Number of Portfolio Holdings	16
Portfolio Turnover Rate	52%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® Disciplined Duration MBS Index Fund	$10	0.20%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$94,025,759
Number of Portfolio Holdings	395
Portfolio Turnover Rate	53%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® Credit-Scored US Corporate Bond Index Fund	$8	0.15%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$697,917,349
Number of Portfolio Holdings	1,653
Portfolio Turnover Rate	27%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® Credit-Scored US Long Corporate Bond Index Fund	$8	0.15%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$35,337,550
Number of Portfolio Holdings	817
Portfolio Turnover Rate	31%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® High Yield Value-Scored Bond Index Fund	$19	0.37%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$1,100,490,809
Number of Portfolio Holdings	958
Portfolio Turnover Rate	54%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® ESG & Climate Investment Grade Corporate Core Index Fund	$6	0.12%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$42,867,571
Number of Portfolio Holdings	720
Portfolio Turnover Rate	39%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® Ultra-Short Income Fund	$13	0.25%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$1,404,338,078
Number of Portfolio Holdings	248
Portfolio Turnover Rate	21%

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Table Summary
Fund	Costs of a $10,000 investment^{Footnote Reference*}	Costs paid as a percentage of a $10,000 investment^{Footnote Reference*,}^{Footnote Reference1}
FlexShares^® Core Select Bond Fund	$10	0.21%

Footnote	Description
Footnote^*	Reflects applicable expense reimbursements and fee waivers.
Footnote¹	Annualized

KEY FUND STATISTICS

Table Summary
Net Assets	$168,905,407
Number of Portfolio Holdings	22
Portfolio Turnover Rate	73%