ProMag magazines are designed utilizing both traditional stamping and welding of heat-treated high carbon steel, and modern precision injection molding of mil-spec polymer compounds. Every ProMag magazine is backed by a lifetime guarantee against manufacturers defects. Made in USAFeatures :20-round magazineFits FN SCAR 17 7.62x51mm /.308 rifleMagazine body constructed of a proprietary DuPont Zytel based polymerInjection molded magazine followerMagazine spring formed from heat treated chrome silicon wire Made in USA