30-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 USA