The Mossberg 500 Mariner applies a Marinecote finish — a proprietary salt-spray-resistant coating — to all metal components for marine and coastal use. The Marinecote finish is functionally similar to stainless steel in corrosion resistance but applied over standard steel rather than requiring stainless alloy. Type: Shotgun Action: Pump-Action Caliber: 12 Gauge Capacity: 6 Year introduced: 1988, USA Weight: 112 oz Overall length: 38.5" Status: Active Intended use: Maritime, Home Defense, Marine Use