These files are specifically designed for levelling out vulnerable edges and can prevent excessive material loss during the final finishing stage of your project. Smooth out scratches left behind from your coarser grits resulting in a perfect finish. 3/4” (20mm) Professional Hobby Sanding Files give you plenty of feedback that prevents excessive material loss. The key to great results is using the proper progression of grits. Always work from coarse to fine in order to remove any scratches, dents, or imperfections. These files are light-weight, waterproof, washable, and reusable making this product a must have.