The MX-15 M-Lok free-float rail features a slim profile for improved ergonomics and weight savings. With a static top rail optimized for mounting optics and multiple contact points for a hex key mounted modular rail system on the sides and bottom, the MX-15 Rail is the ideal solution for any AR-15 owner looking for speed and mission flexibility. It uses a hex key secured barrel nut clamp and proprietary barrel nut for even more weight savings and easy installation. The Mx rail utilizes a non-indexing barrel nut and clamping system (FREELOK) that utilizes free floating tabs to secure the rail to the receiver. It provides both frictional and mechanical locking forces to create a rock-solid bond between the rail and barrel nut. The rail is constructed of 6061-T6 alumnium with a hardcoat anodized finish. This model is 15" long.