Vixen invented the universal dovetail that is used by many telescope and mount manufacturers. Vixen scopes and mounts all attach via this system. Use to attach your telescope with Vixen Tube Rings or third party rings with 1/4-20 tpi threaded holes. Other devices such as a camera can also be attached. Interchangeable with the GP tube plate. Two 1/4"-20 tpi bolts included.