GG&G GS-1 FIRE System Optical Mounting Rail Flat. This scope rail provides significantly longer eye relief for a proper scope/operator interface and the capability of attaching additional optical devices such as a night vision monocular. The back of the GG&G FIRE Rifle Scope Rail has been tapered to blend with the rear of the upper receiver and is not designed to mount a BUIS flip-up rear sight. It extends three inches over the hand guards and clears the AC forearm. The extended length of the GG&G GS-1 Optical Mounting Rail gives AR-15 and M-16 users an advantage in numerous tactical situations. The GG&G Scope Mounting Rail allows for accuracy at greater distances approaching what you would expect for a bolt action rifle. This allows for more cover choices a higher degree of stealth and increased survivability in police and combat situations. Furthermore the GG&G GS1 Extended Scope Ring Rail gives the M16 and AR15 operator more personal choice in selecting a preferred optical configuration which may previously have been unmountable. Manufactured from billet 6061 T6 aluminum alloy and Type III black hard-coat anodized the GG&G GS-1 Rail meets MIL-STD-1913 standards. As with the other GG&G FIRE System Rails it locks onto the flat top receiver by means of a full length locking side bar and two rounded socket head cap screws. The socket head wrench required for installation is included. Specifications for GG&G GS-1 Optics Mounting Rail: Material: 6061 T6 Aluminum alloy Finish: Type III hard-coat anodized black Features of GG&G Scope Rail GS1: Extended length - allows longer eye relief room for additional optics Machined from billet aluminum Package Contents: GG&G GS-1 FIRE System Optical Mounting Rail