Feature: 1. This whetstone is made of high quality materials, is very hard, wear resistant, and can maintain its shape well. 2. The structure is delicate and compact, with a hardly abraded surface and high hardness. 3. Just add a few drops of water when sharpening, the sharpened blade is very sharp, suitable for sharpening and fine grinding of the knife. 4. It is suitable for workpieces with high finish requirements such as precision measuring tools and instrument parts. 5. Suitable for processing hardened steel and alloy steel with high toughness. Specification: Item Type: Sharpener Material: Ruby Purpose: Industrial Tool Grinding Basic Parameters: Roughness: 3000 Mesh Specification: Cylindrical Length 100 mm/3.94in Diameter: 2mm / 0.1in, 3mm / 0.1in, 4mm / 0.2in, 6mm / 0.2in, 8mm / 0.3in, 10mm / 0.4in . Package List: 1 x 2mm Sharpener1 x 3mm Sharpener1 x 4mm Sharpener1 x 6mm Sharpener1 x 8mm Sharpener1 x 10mm Sharpener Note: Put it in a safe place, and be careful not to drop it from a high place.