The Winchester SX4 (Super X4) is a 3-inch gas-operated semi-automatic featuring the Active Valve gas system, which uses a self-regulating pressure valve to adapt between light and heavy loads without manual adjustment. It is manufactured in Belgium by FN Herstal and positioned as a premium domestic alternative to Italian inertia guns. Type: Shotgun Action: Semi-Automatic Caliber: 12 Gauge Capacity: 4 Year introduced: 2017, Belgium Weight: 208 oz Overall length: 49" Status: Active Intended use: Hunting, Waterfowl, Sport