Naniwa #220 IO-1142 Japanese sharpening flattening stone This is for finishing grindstone.Particle size: Extra fine #220 it is possible to continue sharpening to clean the kitchen knife at the grindstone Size 6.7x1.2x2.2inches This is for a whetstone which corrects the field of its level. Sharpening flattening stone support behind the grinding wheel is a very important presence.