The Mirka 6-Inch 6-Hole 180 Grit Dustless Hook and Loop Sandpaper discs have a special sharp, durable aluminum oxide grain that gives you fast and exceptionally long-lasting results. Durable aluminum oxide, combined with urea resin over glue bonds and an open coat, creates a high performance sandpaper. These hook and loop sanding disks are 180 grit, are sold 50 per box, and fit DeWalt DW443, Porter Cable 335, 97366, and Bosch 3727DVS.