Ammco Adapter Plus System is the easy way to do all of your hubless work. The deluxe set will do all of your: Passenger car hubless rotors and drums up to 4" center hole sizes All composite car and truck rotors 1/2 ton trucks rotors and drums up to 4" center hole sizes Works with any model Brake Lathe with 1" Arbor Shaft. Set includes: Adapter Description Dimensions 47300 Hubless Adapter 10438 Small Adapter Cup with built in spring 5.25" OD 10436 Small Backing Plate 5.25" OD 10439 Large Adapter Cup with built in spring 6.75" OD 10435 Large Backing Plate 6.75" OD