Japanese Wet Stone 13,000 Grit from Satake is a whetstone that gives an extremely fine finish. Ideal for polishing and maintaining already sharp knives, it should be used in conjunction with a coarser whetstone of at least 3000 grit. Whetstones are graded according to grit, or degree of fineness, depending on the purpose of the grinding. Satake sharpening stones are color coded for easy grit level identification, and the packaging matches the color of the stone for added convenience.