Aluminum accessory rail bolts to the underside of the standard factory plastic handguard to enable fast, easy mounting of lights, vertical grips, bipods, and other accessories. The "UFIR" features 11 cross slots machined to MIL-STD-1913 specifications to provide a variety of accessory options depending on the mission. Attaches to the underside of USGI-style plastic AR-15/M16 rifle or M4-style carbine handguard using the included mounting hardware. Mfg: Gg&G SPECS: 6061 T6 aluminum, mil-spec Type III hardcoat anodized, matte black. 45/8" (11.7cm) long. Steel mounting hardware included.