When selecting a head for a your Coats tire changer, reference the second picture shown on this page. The stub sticking out of the shaft that holds the head will be either tapered (smaller on the bottom than the top) or it will not be.
Heavy Duty Car Ramps 2 Pack Low Profile Vehicle Tire Lift Service Ramps
Mount head for Low Profile Tire fits Coats®* Tire Changer Mount Demount Head
Tire Changer Low Profile mount demount plastic Gray Fits Coats ® 184432
Low Profile Grey Nylon Mount / Demount Head Kit for Coats
2 Pack TC184432 8184432 Low Profile Nylon Mount/Demount Head Kit Fit for Coats