SurfPrep non-woven discs & pads are 3-dimensional and highly flexible. The flocked backing is to be used on SurfPrep Sanders with Hook & Loop backup pads (H&L). No vacuum holes are needed for vacuum sanding, the substrate will suck through abrasive and flocking. Maroon pads have a multitude of uses, from defuzzing of white wood to scuff sanding between sealer coats on wood. These are also used in the automotive industry for prepping metal surfaces before paint.