50-round drum magazine Fits 9mm AR-15 carbines using GLOCK type 9mm magazines Drum housing constructed of a proprietary DuPont Zytel based polymer Magazine upper tower has full length steel internal insert stamped and welded like the factory magazine Injection molded magazine follower Magazine spring formed from heat treated stainless steel Flush Fit drum magazine for use in Glock type magazine Made in U.S.A. NOTE : Does not fit Glock Pistols, for use in PCC / 9mm AR-15 using Glock type magazines only.