User Benefits Excellent sanding performance for professional use. Hard wearing paper and Velcro back provide smoother finish and longer paper life. Application: Sanding wood, Regular steel and painted wood. Decorating. Features: Extra hard wearing aluminium oxide and velcro backed paper Pack of 50 Hole: 3+3 Compatible with: BO4554 BO4561 : Hitachi Material: Wood, Regular steel and 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.