The Mossberg 590 Mariner features Marinecote stainless-like finish on all metal surfaces to resist saltwater corrosion, making it the premier pump-action shotgun for marine and coastal environments. Type: Shotgun Action: Pump-Action Caliber: 12 Gauge Capacity: 6 Year introduced: 1990, USA Weight: 7.5 oz Overall length: 39.5" Status: Active Intended use: Marine/Tactical