The AR Cantilever Mount Rings for 30mm and 1" Rail by Barska offset mounting rings and allow the mounting of longer rifles copes on your flat top AR-15. The extra room provided by these rings allows you to align the rifle scopes eyepiece directly above the rifles charging handle. Includes 6 heavy duty screws to keep the optic in place and a large thumb lock screw keep the mount securely on firearm. Rifle scope not included.