Trinity Force YGM418ML15: The KMX Series M-LOK Free Float Rail features a slim profile for improved ergonomics and allows the shooter a modular platform using the M-LOK rail attachment system.The KMX Series uses the Patented FREELOK Clamping System. Includes a non-indexing barrel nut and clamping system that utilizes free floating tabs to secure the rail to the receiver. FREELOK provides both frictional and mechanical locking forces to create a rock-solid bond between the rail and barrel nut. Designed to be used with pistol length, carbine length, mid-length, or Mil-Spec M16 rifle length gas systems.For your safety, Trinity Force recommends this part be installed by a competent, qualified gunsmith/installer with an understanding of the weapon platform that the part is being installed on. Always make sure the firearm is unloaded and pointed in a safe direction when working.