Milwaukee Spindle Washer is designed for 4" &amp; 5" cup wheel guards, 9" sanders/grinders, 7" heavy-duty polishers, 7" heavy-duty variable speed polishers, 7" &amp; 9" disc sanders, 9" grinders and more. The washer is made of nylon and is used to remove the threaded cup wheel from the spindle.<br /><br />