Girsan MC312, Inertia Driven Semi-automatic, 12 Gauge, 3.5 Chamber, 28 Vent Rib Barrel, Marsh Camo Finish, Polymer Stock & Forend, Screw-in Chokes, 5 Rounds 390150 Out of the box the MC312 runs 12GA 2.75", 3" and 3.5" shells and has passed 10,000 round endurance testing without having any parts replaced!