Mossberg 590M Double Stack Shotgun Magazine 12 Gauge 15 Round Black 1 Pack Polymer 15RD. 75in shotshells only. Patented double-stack design for use exclusively with the Mossberg 590M Mag Fed pump-action Shotgun. Features hardened steel feed lips over-molded shell ramps easy grip molded design proprietary self-lubricating polymer magazine body material removable floor plate for easy cleaning and a tough black oxide finish on the steel components. Specifications for Mossberg 590M Double Stack 12 Gauge 15 Round Shotgun Magazine: Manufacturer: Mossberg Color: Black Fabric/Material: Polymer Magazine Capacity: 15 Round Gauge: 12 Gun Make: Mossberg Package Contents: Mossberg 590M Double Stack 12 Gauge 15 Round Shotgun Magazine Mossberg 95139-15RD: 590M Double Stack Shotgun Magazine 12 Gauge 15 Round Black 1 Pack Polymer