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 Modified Full and Extended Turkey 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