The Mossberg 590A1 18.5-inch is a compact mil-spec pump shotgun with parkerized finish, metal trigger guard, and heavy-walled barrel for military and law enforcement use. Type: Pump-Action Shotgun Action: Pump-Action Caliber: 12 GA Capacity: 8 Year introduced: 1987, USA Weight: 7.5 oz Overall length: 38.5" Status: Active Military use: Yes Intended use: Military, Law Enforcement, Tactical