Combat Armory Complete Rifle AR-15 Rifle is built to Mil-Spec out of Billet 7075-T6 aluminum and hard-coat anodized black. It comes with all Mil-Spec components installed.Features: Barrel Length: 16" Barrel Material: 4140 Chrome Moly Vanadium Barrel Finish: Melonite Barrel Profile: M4 Barrel Thread Pitch: 1/2X28 Chamber: 5.56mm Twist Rate: 1:7 Barrel Extension: M4 Feed Ramps Gas System: Carbine Length Gas Block Type: .750 Low Profile Gas Block Muzzle Device: A2 Flash Hider Upper Receiver Material: Billet 7075 T6 Upper Receiver Style: M4 MIL-STD Upper Receiver Finish: Type III Anodizing Forward Assist: MIL-STD Dust Cover: MIL-STD Handguard Type: Free Float Handguard Style: M-Lok Slim Rail Handguard Length: 15" Charging Handle: MIL-STD Lower Receiver: Billet 7075 T6 Lower Receiver Finish: Type III Anodizing Safety: MIL-STD SYLE AMBI Fire Control Group: MIL-STD Buffer Tube: Pistol Tube Magazine: 5.56 10 Round