This is an SGM 9mm 50rd. Drum Magazine for Glock Pistols. SGM's high-capacity magazine is designed for Glock 9mm pistols. Heavy duty black polymer drum magazine is easy to load, with integral spring tension releasing cam. Move the cam, drop in a round and repeat until the magazine is full. Capacity of 50rds. Works in all 9mm Glocks pistols and most other carbine rifles designed to use the Glock 9mm magazine including the Kel-Tec Sub 2000.