Smirdex sanding sheet used mainly for manual work or hand sanders. The sanding grains (grit), contained per square millimeter in the product, amount to K100. The higher the sandpaper number, the higher the grain density per square millimeter. So in the small numbers (e.g. 24, 36, 40...), we have few grains but of a large diameter that make them ideal for quickly smoothing rough surfaces, while in the large numbers (e.g. 180, 220, 320...), we have more grits with a smaller diameter and are ideal for intense sanding and a smooth finish. You should also know that when sanding with a sander the action is clearly greater than by hand. Its dimensions are 230x280mm. The package contains 1pc.