The Promag AR-15 10-Round Magazine fits AR-15 rifles chambered in .223 Remington and 5.56 NATO. The short 10-round body sits low under the receiver, which suits bench shooting, hunting and anywhere a 10-round limit applies. It also makes a handy loading and function-test magazine for a new build. The body is built from a proprietary DuPont Zytel-based polymer. The patented anti-tilt roller follower reduces friction as rounds feed, and the spring is wound from heat-treated chrome silicon wire. Each step of assembly is checked for consistency, and Promag magazines are made in the USA with a lifetime guarantee against manufacturer defects. Features: 10-round capacity Fits AR-15 .223 Rem / 5.56 NATO rifles DuPont Zytel-based polymer body Patented anti-tilt roller follower Heat-treated chrome silicon wire spring Black, made in USA Before you depend on it: load the magazine fully, seat it until the magazine catch clicks, and run it through your rifle to confirm it feeds and locks the bolt back on empty.