High Density Material - DBOO sanding blocks are made of high density sponges as bases and high quality aluminium oxide with special treatment. Lightweight and flexible, less sand loss and longer service life. The size of each sanding block is 10 x 7 x 2.5cm, perfect size for gripping. 6 Different Specifications - Package totally includes 6 pieces sandpaper sponges of 6 different coarse and fine specifications assortment in 60/80/100/120/180/220 Grits: 2 pcs Coarse (60~80) + 3 pcs Medium (100~180) + 1 pcs Fine (220). Tips for Using - The smaller number means the coarser grit and the higher efficiency of polishing, but the rough the grinding effect. Suggest to use according to article characteristics and burnish requirements. Tips : First can choose the small number ones for roughing and then choose the larger number ones for fine processing. Wet and Dry Dual Use - Great for both wet and dry use, this sand block is washable and reusable. it can reduce flushing and improve work efficiency. It also can be rinsed with water, easy to clean, please dry the water after every use. Great Flexible Sanding Sponge - It can be returned to its original shape after being rotated 360 degrees. It can also be bent to the desired angle for easy sanding. Great for wood, glass, paint, metal, plastics, porcelain or drywall. Suitable for all kinds of small polishing work, can grinding any irregular geometric curved surface, portable and handy.