18 416 SST Barrel (1:7 Twist) - .750 Rifle-Length Gas System - Diamond-Honed Nitride M16 BCG (6.5 Grendel Bolt Face) - APF 3.5 lb. Drop-In Trigger - APF Adjustable Gas Block - APF Butcher-16 Muzzle Break - Magpul ACS Stock - Magpul MOE Grip - APF 15 M-Lok Handguard - Billet Receiver Set - Ambidextrous Controls - Caliber/ Gauge: 22 Arc - Barrel Length: 18 416 SST Barrel (1:7 Twist) - Action: Semi-Auto - Front Sight: Rear Sight: None - Color: FDE - Finish: Cerakote - Material: Aluminum - Hand: Right