The Mec-Gar 1911 9mm 10rd Anti-Friction with Plastic Floorplate Mag is a 10 round high cap 9mm magazine. It features a carbon steel tube that is heat treated for strength and a higher tensile music wire spring. It also has a lubricated nylon polymer follower with a metal insert where the slide stop activates to properly align all types of ammunition for the most reliable feeding. The high impact polymer removable butt-plate is tapered to fit funneled mag wells. The anti-friction coating allows for easy loading and superior anti-corrosion properties. Please note this magazine will not work with STI pistols.