A precision cut AR15 magwell adapter shim to fit Smith & Wesson M&P 15-22 magazines making them the correct fit for AR15 .22, KRISS and SIG 522 magwells.
Sold individually, one adapter needed per magazine.
M&P 15-22 magazines are slightly shorter front-to-back than an AR15 magazines, this was to prevent full size mags being accidentally fitted to an M&P15-22, but means they are loose in regular AR magwells which can result in feed issues.
When fitted to the front of the M&P15-22 magazine the precision cut 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, including the Kriss Defiance.
Importantly M&P 15-22 magazines operate the Catch22 bolt hold open catch and Kriss Defiance mechanisms with 100% reliability when fitted on AR15 .22s.
The precision cut plastic shim has a slippery surface finish with a very strong 3M adhesive layer, just peel off and apply.