Proxxon sanding belts for Proxxon belt sander BBS/S, number 38526. replacement sanding belts made from high quality aluminum oxide on tough, woven, lightweight cloth backing for use on metal, non-ferrous metals, wood and plastics. belt size 1-37/64-Inch by 10 7/16-Inch (40 by 265mm). Contains 5 each of 120 grit belts.