The ProMag Magazine features a magazine body constructed from a proprietary DuPont Zytel based polymer. The follower is injection molded and the magazine spring formed from heat treated stainless steel wire. FeaturesMagazine body constructed of a proprietary DuPont Zytel based polymerInjection molded magazine followerMagazine spring formed from heat treated stainless steel DISCLAIMER: This product is not manufactured, authorized, endorsed, or warranted by GLOCK. GLOCK does not warrant or represent that this product is compatible with GLOCK pistols.