Hera Integrated Rail System Keymod for the .308 AR-10 Rifle.The Hera Arms Keymod is a modern designed, Quad-Rail Handguard made from high-quality aluminium and is built to handle the hardest use and abuse of tactical and competitive shooting. The Keymod handguard is CNC milled from aluminium alloy and hard coated anodized for added strength.The 15'' KeyMod handguard comes with its own barrel nut where the handguard is clamp mounted with 3 screws for additional strength. The anti-turn millings prevent turning even at the hardest use.