Vixen Universal Dovetail Tube Plate Includes two 0.25 in.-20 tpi bolts Use to attach telescope with Vixen Tube Rings or third party rings with 0.25 in.-20 tpi threaded holes Other devices such as a camera can also be attached Interchangeable with the GP tube plate Furthest holes are 6.3 apart and center holes are 1.4 in. apart