Fits many ADM Accessories mount adapters as well as the Rainbow Astro RST-300, Losmandy G11 and some Takahashi mounts. Accepts both D Series and V Series dovetail bars. 2 holes 3? apart, 2 holes 35mm apart for a 5/16? or 8mm socket head cap screw. The split clamp design grips the dovetail bar along the entire surface of the saddle and will not dent or scratch the dovetail bar. Features two large locking hand knobs for tool free operation, spring loaded jaws, anodized aluminum and stainless steel construction. 7? Long, 4? Wide, .75? thick, Wt. 26 oz.