This is Japanese Water Stone #400. This stone requires wetting but not full immersion. I am very happy with the results I get with both kitchen knives and utility knives (pocket knives, hunting knives, etc.). If you're just starting out free hand sharpening knives, this works great, but you can start with cheaper stones. This rock needs to be "flattened" from time to time and there are many videos online showing how to do this. You need a whetstone or you can do it with sandpaper. The reason…