If one sees one of these balancers come up for sale look for all of it. The full wheel cover had to come off. The balancing device had to clamp onto the rim. In the middle of it is an assenbly with 4 little smooth wheels, 2 for weight 2 for position. You grasped these lightly while the wheel spun at 40 mph. There were 3 adaptors, for 13, 14, and 15 inch wheels. And if you didnt get them positioned correctly, and tight, it could come off, and take off across the shop. Always felt it was a very accurate balancing method
