ProMag magazines are made in the USA and backed by a lifetime guarantee against manufacturers defects. Magazine springs are precision wound using heat-treated chrome silicon wire and each and every step of the assembly process is checked and double checked in order to maintain the same consistent level of quality.Features :20-Round MagazineFits The Fn Five-Seven Usg 5.7X28MM Magazine Body Constructed of a Proprietary Dupont Zytel Based PolymerInjection Molded Magazine FollowerMagazine Spring Formed From Heat Treated Chrome Silicone WireMade in the U.S.A.