Get the ultimate in capacity and firepower for your Glock® pistol with the KCI® .40 S&W 50-Round Drum Magazine for Glock Pistols. This aftermarket magazine features lightweight polymer construction with hardened steel inserts for unparalleled strength and long-lasting field service. A heat-treated chrome silicon wire spring and tough polymer follower ensure smooth, reliable feeding in high-stress target and defensive situations. Plus, a clear polymer window allows for quick, at-a-glance round counts on the fly. Further, a load assist lever provides quick and easy loading.