These sanding blocks are made with high-quality brown corundum and dense sponges, making them flexible and easy to use. They won't lose sand and will last a long time.

The set includes 6 sanding sponges in different grits: 60, 80, 100, 120, 180, and 220. The lower the grit, the coarser it is and the faster it polishes, but the rougher the finish. You can start with a lower grit and move to a higher one for a smoother finish.

These sanding sponges can be used with or without water, which helps reduce mess and increases efficiency. They're also easy to clean and reuse - just rinse with water and dry after each use.

Each block is 3.94 x 2.76 x 0.98 inches, perfect for handy use. They're great for sanding putty, woodworking, furniture polishing, metal derusting, primer polishing, and other polishing tasks.