Fits V Series dovetail bars. Adds additional weight for balancing OTA s especially the off-center saddle on the OEM Celestron CGEM and CGEM-DX. Split clamp design grips the dovetail bar along the entire surface of the saddle and will not dent or scratch the dovetail bar. The dovetail clamp has a large locking knob for tool free operation, spring loaded jaws, anodized aluminum and stainless steel construction. DPA- 2.5 Long, 4 Wide, .75 Thick, Wt. 10 oz., Counterweight- 4 Rounds, 1 thick, 3.5 lbs.