Standard Steel S15 Magazine Catch Our steel mag catch is required to work with the Shield Arms S15 magazine. Using our steel mag catch with plastic OEM magazines can cause increased wear on plastic mags and OEM mags may not drop free. We do not recommend using our steel mag catch with plastic OEM mags. We recommend steel on steel or plastic on plastic. If you have a first generation aluminum mag catch, it is required to upgrade to one of our steel catch offerings. Description: Steel mag catch, several finish options Ambidextrous Compatible with all generations of S15 magazines Chamfered, textured button Optimized for use with Shield Arms S15 magazines Lower profile for concealed carry Made in the USA 100% lifetime warranty