MATERIAL: The sanding sponges are made from high quality brown corundum, using high density sponges as the base material. Useful and portable. VARIOUS SPECIFICATIONS INCLUDED: 4 medium fine (240-300 grade) sanding sponges in total. Meet your needs. WET AND DRY AVAILABLE: The sand block is washable and reusable, can be used both wet and dry. It is convenient to clean, durable and easy to grip, not easy to tear. WIDE USE: Can be used on wood, paint, metal, plastic or drywall. Suitable for all kinds of small jobs, can grind any irregular geometric curved surface, portable and practical. A good tool for polishing or cleaning. SAND BLOCK SIZE: 4 pcs/pack. Each block measures 3.9 x 2.7 x 1 inch / 98 x 68 x 25 mm. 4 Sponge Sanding Blocks for Wet and Dry Surfaces, Medium Sanding Blocks purposes. Use: Sanding blocks can be used on wood, glass, paint, metal, plastic, porcelain or drywall etc. Technical specifications: Material: brown corundum and high density sponge. Grain: medium thin Dimensions: 98 x 68 x 25 mm. Quantity: 4 pieces in total. Contents: 4 medium fine sanding sponge.