Commercial HK416 derivative with 16.5-inch barrel using HK's proprietary piston system. One of the finest piston AR-15s available to civilians. Type: Carbine Action: Semi-Automatic Caliber: 5.56x45mm NATO Capacity: 30 Year introduced: 2010, Germany Weight: 135 oz Overall length: 36" Status: Active Intended use: Sport Shooting, Tactical, Home Defense