A pair of AR15 magwell shims to make Smith & Wesson M&P 15-22 magazines fit AR15 .22, KRISS and SIG 522 magwells.
Fitted to the front of the M&P15-22 magazine the precision shim makes the M&P15-22 magazine the same length as a regular AR15 magazine. Allowing M&P15-22 magazines to be used in any AR15 lower.
Importantly M&P 15-22 magazines operate the Catch22 bolt hold open catch with 100% reliability when fitted on AR15 .22s.
The precision cut plastic shim has a slippery surface finish and attaches using a strong 3M adhesive layer, just peel off and apply.