The Agena Vixen-style 8" dovetail bar is made of aluminum and features a gunmetal gray finish similar to the color of many equatorial mounts sold today. This will allow you to couple telescope tubes to a telescope mount. It will fit most Vixen, Synta and other mounts that use a Vixen standard mounting base. The dovetail bar is 8" long and 1.57" wide. The 4 holes are all non-threaded and will allow 1/4"-20 screws to pass through. The two holes in the center of the plate are 1.38" apart (center-to-center) and the two holes at the edges are 6.30" apart. Please check the detailed product dimensions in photo 3 above to determine compatibility with your mount. Weight = 5.1oz / 145g.