These counterweights are quite a bargain, concentrating a log of weight (10kg) into a single spot on the counterweight shaft. Excellent for 1.25" or 32mm applications. I used them on a 30mm counterweight shaft, by putting in a thin teflon sleeve made of adhesive teflon material. The finish is not "perfect", but is surprisingly good for counterweights from this source, and the knobs are easy to use and effective. There is a non-marring plastic tip on the securing bolt end.
This extra counter weight is required for the use of the Celestron Guidescope.