Replacement foot care rollers for removing particularly hard calluses, using diamond powder. - Brand: Dr. Scholl - Product Name: Velvet Smooth - Quantity: 2 rollers x 2 packs - Features: Contains diamond powder Thank you for viewing. These are replacement roller heads for the Dr. Scholl Velvet Smooth electronic callus remover. They contain diamond powder and are the extra (coarse) type. If you have the main unit, please use these.