I’ve deleted this post about Counterweight & Shaft choice as I work my way through the set-up procedures
Post deleted for now
Sky-Watcher Wave Mount Counterweight works great with the WD-20
The SW 150 kit did not work well for me - the main shaft is too thick to fit in the Counter Weight hole in the mount. The extension bar did fit & also fit as an extension to the ZWO bar, which fits. So, I have been able to use the extension bar & the weight from the kit, but not the main bar