Kasumi Knives are produced by the Sumikama Cutlery factory in Seki Japan. Sumikama specializes in producing knives from the most advanced materials, with the most advanced manufacturing techniques. Kasumi Sharpening Accessories are designed specifically for use with Kasumi knives, but can be used for any Japanese knife brand. Always follow the sharpening instructions on the packaging. Professional ceramic whetstone - soaking is not required Super Fine 5000 grit side for polishing an edge to a razors finish Ultimate 10000 grit final touch up side for the perfect edge A rubber base to hold the whetstone and prevent slippage is included Use this sharpener with your Kasumi brand knives, and any other slim Japanese style blades Made in Japan