3″ to 4-1/2″ to 5″ backing plate. Used for high speed air grinders Backing plates has the high strength Epoxy fiberglass construction. 2 degree taper formed center -7/8″ hole. Size from 3″ to 9″ to fit all grinders. Eezer 4300Made in USA Click Here. Double your traffic. Get Vendio Gallery – Now FREE!