Trinity Force RUSA15: This is a brand new product from Trinity Force! The 15\" Trinity Force M-LOK Free Float Rail features an ultra-slim profile with front and rear Picatinny attachments. Also included are 4 polymer Picatinny rail attachments with steel hardware. and an all-steel barrel nut is included alongside shims for correct fitment. Designed to be used with mid-length, rifle length or Mil-Spec M16 rifle length gas systems. The EMR 15\" M-LOK Rail is made with pride right here in the U.S.A.