Colt's Manufacturing M4 Carbine. Knights Armament Rail System. Extended flash hider has been pinned and welded to achieve a non-NFA length of 16.1". Includes the side sling swivel at the gas block, Tango Down Stubby Fore Grip and Original Fore Grip, BCM Grip And Original M4 Grip, Matech Rear Flip-Up Sight, Magpul Sling, Magpul Stock And Original Stock