Japanese water stones are an efficient and effective tool for keeping your knives sharp. Using just a few drops of water (no pre-soaking required), your knives will be sharp in a matter of minutes - no oil necessary. This TWIN Pro 250/1000 Combination Japanese Water Stone has two sides, a coarse 250-grit stone for especially dull knives or reshaping blades, and a fine 1,000-grit stone for the finishing touches. The base has non-slip rubber feet so you can safely sharpen your knives on most surfaces.