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, metal, decorating, confined areas, detail sanding Features: Extra hard wearing aluminium oxide and Velcro backed disc, with 8 holes for dust extraction. Pack of 10. Hole: 8 Compatible with: BO5012 BO5010 BO5021: Bosch BD DeWalt AEG Milwaukee Metabo Festool Material: Wood, regular steel.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. Grade of Grit Common Name Uses 40-60 Coarse Heavy sanding and stripping, roughing up the surface. 80-120 Medium Smoothing of the surface, removing smaller imperfections and marks. 150-180 Fine Final sanding pass before finishing the wood 220-240 Very Fine Sanding between coats of stain or sealer. 280-320 Extra Fine Removing dust spots or marks between finish coats 360-600 Super Fine Fine sanding of the finish to remove some luster or surface blemishes and scratches.