Features 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 Sharpener 1 x 3mm Sharpener 1 x 4mm Sharpener 1 x 6mm Sharpener 1 x 8mm Sharpener 1 x 10mm Sharpener