Patented double-stack design, Designed exclusively for the Mossberg® 590M Mag-Fed Shotgun, the Mossberg 590M 12-Gauge 15-Round Magazine features an easy-grip, self-lubricating polymer body with a patented double-stack design for unmatched reliability and maximum firepower in a compact magazine. The hardened steel feed lips deliver a snug, wobble-free fit, while the over-molded shell ramps and high-tensile steel spring deliver smooth, jam-free feeding performance. Better yet, this magazine features a removable floor plate for quick disassembly when maintenance and cleaning are required, and a tough, black oxide finish on all steel components for superior corrosion resistance and improved durability in virtually any environment.