3 Picatinny Rails For The Original Hand Guard For AR15/M4 Transfer your original handguards, to a full Picatinny System. Set of two 45 degree Picatinny rails and one removable center rail. Mounted to the upper or lower handguard. Excellent for mounting lasers, flashlights, vertical grips, pods and more. Fits both, standard and thickened heat shields.