This 22-rd magazine is for the German Sports Guns GSG-5 in .22lr. It features an injection molded housing and follower constructed of impact resistant glass filled nylon polymer for durability. The spring is precision wound from heat treated Chrome-silicon wire for reliable feeding. All components proudly made in the U.S.A.ProMag magazines are designed utilizing modern precision injection molding of Mil-Spec polymer compounds. Every ProMag magazine is backed by a lifetime guarantee against manufacturer's defects. Features: Magazine body constructed of a proprietary DuPont Zytel based polymer Injection molded polymer follower Magazine spring formed from heat treated chrome silicone wire Made in USA