PowerLock Buffing Discs-Type III, 3", CoarseAluminum oxide grain for a combination of cut rate and finishTough, yet conformable, high-strength discs are smear-proof and resist tearing on burrs and sharp edgesType TR/III fit roll-on/roll-off plastic attachment systemAll non-woven QC discs are designed to run on back-up pads that are rated at