Our steel mag catch is optimized to work with the Shield Arms S15 magazine. While it remains compatible with plastic OEM magazines it can cause increased wear on plastic mags with prolonged use 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. - Features - Steel mag catch several finish options - Ambidextrous - Compatible with Gen 1 and Gen 2 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 - Installation Instructions