This 4.5kg counterweight will fit the following iOptron mounts:
- CEM40/CEM40EC (early version with 20mm CW shaft)
- CEM26
- GEM28
- iEQ30/iEQ30 Pro
- CEM25/CEM25P/CEM25EC
- ZEQ25
- AZ Mount Pro
- MiniTower Pro
- MiniTower II
- MiniTower
It can also be used for any other mount that has a 20mm diameter counterweight shaft.