High Quality Material: These sanding blocks are made of high quality brown corundum sandpaper and basic high density sponges, acid and alkali resistant, sturdy and durable, not easy to break.Available wet and dry: the sanding sponge blocks are not only suitable for polishing objects with a dry surface, but also available for wet surfaces because the sponge has good water absorption, guaranteeing a good polishing effect on wet surfaces.Washable and Reusable: These sanding blocks are washable and reusable, very convenient to clean after use, you can just rinse them directly with water. After cleaning and drying, they can be reused.Multiple Function: Widely used in polishing drywall, wood, plastic, paint, stone, metal materials of various complex surfaces, also a good tool for polishing. cleaning in the kitchen. Note: The data is all manual measurement, please allow 1 - 3cm error, due to the difference in light and display, there will be some color difference, depending on the physical object received.