DEWALT DWA8207 60 Grit Zirconia T29 Flap, 4-1/2-Inch X 7/8-Inch Zirconia grit enables 3X faster material removal than fiber resin metal sanding discs Premium abrasive cloth provides up to 15 X longer life than fiber resin metal sanding discs Type 29 fiberglass backing provides grinding angle of 20-25 degrees