Contains long-lasting white aluminum oxide, slightly less aggressive than Garnet Discs and Water Proof Silicon Carbide Discs. Abrasive is glue-bonded onto a thin flexible plastic backing. Flexible and works well on contoured surfaces. Available in 3/4″ and 7/8″ diameters and 4 grits. Max. operating speed: 30,000rpm. Sold in boxes of 50 discs.