MLOK C4 rail system is based off the patented quad rail version. It is a lightweight, rugged, 2-piece free float rail that when installed gives the uppers a continuous 12o clock rail and MLOK slots for the 3,6, and 9 o clock positions. This design allows the installation of the rail on an upper assembly without removing the front sight post or permanently attached muzzle devices. Item is used but in excellent condition.
