Made by YHM. These Four Rail Free Float Forearms utilize anti-rotation screws to insure that the forearm stays solid even under strenuous use. Perfect for use with forwards grips and optics. The barrel nut and forearm tube are made of aircraft quality aluminum and hardcoat anodized to mil.specs. The jam nut is made of steel and plated a black matte finish to match. Included: one forearms tube, one jam nut, one barrel nut, 2 anti-rotation screws. Overall length 9.675 inch, weight 18.2 oz. The Specter forearm is designed to cover the gas block on a Carbine length gas system.