Fein Sanding Sheets use aluminum oxide and a full synthetic resin bond to assure fast material removal, minimum glazing and long tool life. For universal use on almost all materials. Non-perforated, for use with a non-perforated backing pad. Applications include wood, metal, solder joints, GFRP, plastic, paint, filler and leather. These sheets are 100 grit, come in a 20 pack and use hook & loop attachment.