ProMag FNH Black Five-SeveN USG 5.7x28mm Handgun Magazine - 30 Rounds - The magazine has a length of 7.25, and includes a molded grip-sleeve to fill the space between the bottom of the grip-frame and the magazine base-plate. All components proudly made in the U.S.A. 30 rounds Fits the FN Five-seveN USG 5.7x28mm Magazine body constructed of a proprietary DuPont Zytel based polymer Injection molded magazine follower Magazine spring formed from heat treated chrome silicone wire