These GG&G FIRE System rails were designed to mount easily over the integral rails of the M16/AR-15 flat top receiver and work in conjunction with a MAD or A2 Style BUIS flip-up rear sights. As they raise the line of sight by ½- 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 wear associated with quick-release-type mounts. The Scout length rail extends 2 inches beyond the handguards and clears 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. Manufactured from 6061 T6 aluminum alloy, black hard-coat anodized, all of the GG&G FIRE System rails meet MIL-STD-1913. These rails lock onto the flat top receiver by means of a locking side bar and two socket head screws.SOLD.