The combat-proven aluminum based polymer six shotshell carrier is a step forward in design and technology. State of the art design, injection molding and space age high-density plastics are combined to create this which cannot be duplicated in any other material. Designed for military & police personnel. Great for civilians & off duty officers. Modular: mounts directly to the side of the weapon for quick access to shells Part number: TSG-SCM Weapon compatibility: Mossberg 500, 590 , 590da ect 12 gauge shotguns but may not fit variations.