Contents - 12 sanding sponges (4 tiers in each pack). It includes superfine (grade 400500), fine (240320), medium (grade 120180), and coarse (grade 6080) grades. The granularity gets coarser as the number gets smaller. This means polishing will have more effect. Conversely, the larger the number, the coarser the grinding effect. It is suggested to use this item according to its characteristics and polishing requirements. Material and Size: Made with high density sponge as well as small alumina emery. It can be easily washed and reused. Each standing sponge piece measures approximately 100 x 70 x 25mm. Please note that the weight of the sponge varies according to the grades. Neat finishes - The 4 surfaces have been covered with tiny emery alumina. Not only durable but also reusable. The interior contains a durable high density sponge. Very solid. They are also highly resistant to acid, alkali, wear and water. Use and Storage: Perfect for use in both wet and dry form. They can be used to polish a wet object surface. The sponge has a very nice cleaning and polishing effect. It can be adjusted to perfectly fit any shape, thus avoiding waste. Please make sure the water is extruded out after use. After that, should be placed in a ventilated and dry place. This will help ensure that it lasts as long as possible. Nice polishing tool perfect for polishing wood, amber and metal and cleaning kitchen appliances. The sponge is perfect and can work on uneven and flat surfaces. Please note that it should not be used on a boiler liner (high grain non-stick) surface. Product Features: Material : aluminum oxide and sponge. Dimensions: 100 x 70 x 25 mm. Grade Super fine (grade 400 to 500), medium (grade 120 to 180), coarse (60 to 80 grade), and fine (240 to 320 grade). Quantity: Sanding sponges of each grit each come in 3 packs, a total of 12 pieces. Contents: 3 coarse sanding sponges. 3 medium sanding sponges. 3 fine sanding sponges . 3 superfine sanding sponges. Notes: Due to manual measurement, the size may vary slightly. Sanding sponges have no grit mark. They can be distinguished by observing the differences in the surface. The rough surface is much smaller.