12 ga 20 ga or .410 cal 3 magnum chamber gas-operated semi-automatic shotgun – Flawless performance on all 2 3/4 and 3 shot shells – from 7/8 oz to 2 oz magnum loads – FAST Loading System and SMART Valve Piston – Durable alloy receiver – Checkered grip surfaces for better feel and control – Oxidation proof chrome plated steel barrel – All barrels are proof tested at the factory to ensure maximum durability – Cantilever 22mm Weaver optics mount with built-in rear fiber optic sight – Front fiber optic sight – Includes a Full choke – Magazine capacity: 4+1 or 2+1 with migratory plug installed – Stock shims allow adjustment of drop and cast for a better fit – Manual cross-button trigger safety – Mounted sling studs