Best set of whetstone! Good choose for kitchen knife, precision tool, sushi knife and so on Medium Grit (#1000) is also used for corse grit, and Fine Grit (#5000, #8000) is good for finishing Stones are colored with matching ventilated plastic boxes which also serve as stone holders Working surface: 8-1/4 x 2-3/4 x 1/2 in. (210 × 70 × 15mm) Shapton Company in Japan produces the Professional Series line of ceramic sharpening stones. This set of Shapton Celamic Whetstone gives you a nice mix that allow you to repair and meintain (#1000 grit), sharpen (#5000 grit) and smooth (#8000 grit) the edges on your knives. Fine Grit (#8000) is realized a smooth sharpening feel just like a natural whetstone. For finishing and getting a keen well polished edge, may also be used for daily.Each whetstone is * in a plastic storage case that can be used as a stone holder while sharpening. The case has rubber feet help prevent slippage.