Material: The sanding sponge is made of high-quality brown corundum, and the high-density sponge is used as the base material. Useful and portable. Includes different sizes: 4 fine sanding sponges in total (from 240 to 320). Satisfy your needs. WET AND DRY USE: The sand blocks are washable and reusable, can be used wet and dry. Easy to clean, durable and easy to grip, not easy to tear. Wide Application: Can be used on wood, paint, metal, plastic or drywall. It is suitable for various small operations and can grind any irregular geometric surface. It is portable and practical. Great tool for polishing or cleaning. Size of sand blocks: 4 blocks/pack. Each block measures 3.9 x 2.7 x 1 inch / 98 x 68 x 25 mm. Technical data: Material: brown corundum, high density sponge. Granulometry: Fine (from 240 to 320) Dimensions: 98x68x25mm. Quantity: 4 pieces in total Contents: 4 fine sand sponges