This scope mount is perfect for flat top uppers. Great for all types of scopes, red dot sights, and other optics. Raises the equipment 1/2 inch. Can extend rail 1 1/4 inches from upper for greater eye relief and easier access to the charging handle. Weighs just 2.3 oz. Mounts to any picatinny rail, made from aircraft quality aluminum and harcoated to military specifications.