The SkyWatcher Star Adventurer counterweight is designed primarily for the manufacturer's Star Adventurer mounts. However, it can be used with the SkyWatcher AzGti mount (M8/M12 thread reducer required), or possibly other similar products.
The outer diameter of the counterweight is approximately 50 mm, the counterweight shaft is 12 mm in diameter and has an M8 thread on the end for attachment to the mount.