The C210 Clamping Dish designed to fit onto wheel balancer lock nuts and provides a wider / larger surface area to contact the wheel face. Especially suitable for wheels that have and large hidden bolt area where the small CBP cup falls inside of.
When carrying out wheel balancing on modern alloy wheels you should be using the “back cone” method of balancing. (For simple breakdown of front coning and beck coning Click Here)
The C210 Clamping Dish is used along with the lock nut to facilitate this method.