This 50-round drum magazine from ProMag is compatible with Glock 22 and Glock 23 40 S&W pistols.The drum housing is constructed of a proprietary DuPont Zytel-based polymer while the upper tower has a full-length steel internal insert stamped and welded like the factory magazine.The magazine's spring is formed from heat-treated stainless steel wire and has an injection-molded magazine follower.ProMag Glock 22/23 Drum Magazine40 S&W Caliber50 Round CapacityFits Glock 22/23 40 S&W PistolsOrder your ProMag Glock 22/23 40 S&W magazine online today!Searching for 40 S&W? Score big savings when you shop our large selection of cheap .40 Cal ammo for sale.Score big savings and fast shipping on all your favorite Glock Firearms and Accessories available online at Ammunition Depot.