Description 10.5 4150CM Nitride-Coated Barrel – .750 Carbine-Length Gas System – Diamond-Honed Nitride M16 BCG – APF 4.5 lb. Drop-In Trigger – APF Adjustable Gas Block – SBA3 Pistol Brace – Magpul MOE Grip – APF 9 M-Lok Handguard – Billet Receiver Set – Ambidextrous Controls – Caliber/ Gauge: 5.56 NATO – Barrel Length: 10.5 4150CM Nitride- Coated Barrel (1:7 Twist) – Action: Semi-Auto – Front Sight: Rear Sight: None – Color: Blue Shark Gray – Finish: Cerakote – Material: Aluminum – Hand: Right