These unique forearms feature diamond shaped heat vents an extended top rail for gap-free installation T marked rails to mark accessory locations they accept our end caps and utilize our anti-rotation screws for secure installation. The forearms and barrel nuts are made of 6061-T6 aluminum and hardcoated to military specifications. The jam nut and anti-rotation screws are steel and plated a matte black finish to match. – All assemblies include – One jam nut – One barrel nut – Two anti-rotation screws – One forearm tube – Overall Length 7.2 – Weight 12.5 oz. – Hardcoat Anodized matte black to Military Specifications or better