This optical mounting rail was designed to mount easily over the integral rail of the AR15/M16 flat top receiver. As these rail mounting brackets raise the line of sight by 1/2 inch, they offer a proper cheek weld when optical devices are attached. In addition, they serve to protect the flat top receiver's integral rails from the damaging wear associated with lever type quick-release mounts, especially those without buffer pads.
The Scout Rail extends two inches beyond the upper reciever and cantilevers over the handuards including the M4 forearm. It was developed to accommodate long-eye-relief "scout"-type scopes and also Aimpoint red dot sights with night vision monoculars mounted to their rear.