The A.R.M.S. #22 TRR Tactical Ring Rail allows the mounting of devices to the top of a scope ring. It offers an additional base to scoped rifles for the mounting of other equipment and accessories such as lights, lasers, or auxiliary sighting devices. This mount requires the use of the #22 Tactical Ring Cap and is compatible with #22M68 spacers for additional height when using optics with tall elevation adjustment knobs. Comes complete with two mounting screws. Mfg: A.R.M.S.,Inc Specs: Ring Rail mounting base, Black finish, Mounting screws included.