PANZER ARMS M4 MARINE TACTICAL is a semi auto tactical shotgun chambered for 12 gauge shells, and has a 3" chamber. Features include an 18.5 inch barrel, ghost ring sights, a fixed stock, picatinny optics rail, and a 5 round capacity. Nickel and Black. This is a highly durable and reliable weapon designed for use in harsh marine environments. Constructed with a reinforced polymer stock and a stainless steel barrel, this shotgun is built to withstand the corrosive effects of saltwater and other elements. It features an 18.5-inch barrel, which allows swift maneuverability in a confined space.