The LG Universal Long Gun Mount with Accessory Rail System is constructed of aircraft-grade anodized aluminum. This self-locking mount uses an adjustable mount design to easily mount and lock to your long gun, no tools required. The LG adjusts to fit shotguns, all rifles and most scopes. Protective rubber inserts protect your gun and accessories when mounting. The clamp offers a 12.5 millimeter adjustment allowance. The barrel and flashlight portion of the clamp adjusts 20mm to 32.5mm. The side of the mount has an accessory rail mount to attach additional firearm accessories.