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