The second generation Brownells 1911 magazines combine heavy duty construction with the reliability you've come to expect from a century old service weapon. The body and follower are constructed from heat treated stainless steel, with witness holes for a fast round count. Xylan~ exterior coating provides corrosion protection, as well as a slick, friction reducing finish. The anti-tilt follower is mated with an extra-power spring. The removable polymer base pad allows easy disassembly, as well as drop protection when changing magazines on the fly. Cartridge : 9mm Luger