16 4150CM Nitride-Coated Barrel (1:7 Twist) - .750 Mid-Length Gas System - Diamond-Honed Nitride M16 BCG - APF 4.5 lb. Drop-In Trigger - APF Adjustable Gas Block - Magpul MOE PR Stock - Magpul MOE Grip - APF 15 M-Lok Handguard - Forged Receiver - Caliber/ Gauge: 5.56 NATO - Barrel Length: 16 4150CM Nitride- Coated Barrel - Action: Semi-Auto - Front Sight: Rear Sight: None - Color: Copper FX - Finish: Cerakote - Material: Aluminum - Hand: Right