1. ADAPTIVE DESIGN : Longboard hand sanding file block has a rotating handle and a rear groove, which is flexible and convenient, and can easily adjust the appropriate flat and curved surface curvature. This hand sanding block maintains that angular shape throughout the sanding process, allowing you to maintain the same profile as you sand. 2. HIGH QUALITY MATERIAL: Multifunction manual sanding tool is made of lightweight polyurethane foam, which is durable, elastic and not easy to break, it can achieve perfect surface treatment and improve the work efficiency of related workers. Ergonomic design, easy to hold. For use with PSA Sandpaper and PSA Roll Sandpaper. 3. EXCELLENT PERFORMANCE : Our adjustable hand grinding board is designed to be lightweight and unique, which not only allows for better control and smooth sanding results, but also covers a larger area for excellent performance. Size: 7cmx40cm/2.76 inchesx15.75 inches, it requires using 70mm mesh sand or two pieces of 70x198mm sandpaper. 4. WIDELY APPLICABLE : Back groove hand grinding board can be easily adjusted to concave and convex shapes, providing you with the ideal angle for your sanding needs. Our hand sander is a versatile tool for a variety of projects, it is suitable for woodworking polishing, car waxing, wall sanding, rust removal, paint removal and other DIY projects.