Excellent sanding performance for professional use. Use dust extraction for better finish and improved health. Velcro fitting provides smoother sanding, perfect for use with random orbit sanders. Application: Sanding wood, regular steel and floor sanding. Features: Extra hard wearing aluminium oxide and velcro backed disc, with 6 holes for dust extraction. Pack of 10. Hole: 6 Compatible with: BO6030 BO6040: Bosch BD DeWalt Metabo Material: Wood, Regular Steel, Painted Wood.How Do I Know What Grit of Sandpaper I Need The grit you use depends on what job you are trying to do. The lower the grit the rougher the sandpaper and conversely, the higher the grit number the smoother the sandpaper. The table below gives you an idea of what grade you may need for your application.