MK116 PRO Specs: SKU: 19-PM116UA0B UPC: 811154030955 Operating System: PWS Long Stroke Piston System, 3 setting Adjustable Gas Regulator Caliber: .223 Wylde Barrel Length: 16.1" Gas System Length: Mid-Length Barrel Twist Rate: 1:8 Muzzle Velocity: 2980 fps Muzzle Device: A2 Flash Hider Upper Receiver: PWS Proprietary Piston Upper, 6061 extrusion, Anodized Handguard: PWS M-Lok(TM) 15" Handguard (1.7" width, 2.25" height) Charging Handle: Radian Raptor(TM) Ambidextrous Charging Handle