Two-piece, four-rail handguard installs easily and gives flattop receivers a continuous 12 o'clock rail. Clamps directly to standard barrel nut and features T-marks for proper optic and accessory remounting reference. Machined aluminum construction combines strength with light weight. Carbine Cutout model extends rails A 3/4" around sides of front sight base on carbine-length gas systems. Mfg: Centurion Arms SPECS: 6061 T6 aluminum, hardcoat anodized, matte black. 2.1" (5.3cm) wide. 2.38" (6cm) high. 1.37" (3.4cm) inner dia. Includes mounting hardware and instructions.