Block sanding sheets are designed to be used with Mirka?s 3 x 5? (81x133mm) sanding tools. These abrasives are ideal for sanding small defects by machine to quickly level the surface to match the surrounding profile. When used with a dust extractor or the Mirka MR-35SGV self-generating vacuum sander, conventional 8-hole paper reduces dust and net sheets offer almost totally dust-free finishing.