Magpul Industries, PMAG D-50, 9MM, 50 Rounds, Drum, Fits Double Stack 9MM Glocks, BlackLightweight but incredibly strong, Magpuls PMAG D 50 GL9 is a highly reliable, 9x19mm Parabellum, 50 round drum magazine optimized for double stack 9mm Glock handguns. Featuring their innovative bolt hold open, the D 50 reliably locks the bolt back on empty when used with firearms designed to lock back on Glock pattern magazine followers as well as a rounds remaining rear window, a high visibility follower and a capacity indication roller. Features :