4 X 21 1/2 Inch Silicon Carbide Sanding Belts, 3 Pack. Silicon Carbide (S/C), closed coat, heavy duty Y weight polyester cloth backing. High quality and long lasting industrial abrasive sanding belts provide a sharp and long lasting cut on glass, stone, granite, composites, wood, plastics and metal. Heavy duty Y-wgt material provides extra strength for working with grinding and smoothing applications, Resin over resin bonding. Bi-directional tape joint. Wet or Dry applications. Assembled in America.