Aluminum oxide grain for a combination of cut rate and finish. Tough, yet conformable, high-strength discs are smear-proof and resist tearing on burrs and sharp edges. Type TR/III fit roll-on/roll-off plastic attachment system. Designed for light removal of paint or rust without affecting the base product. All non-woven QC discs are designed to run on back-up pads that are rated at or above the RPM of the grinder.