This medium grade ceramic whetstone is suitable for sharpening all straight edged knives.
This whetstone from Wusthof is two-sided. The grey side is coarse (400 grit) and suitable for aggressively removing metal from small flaws in the blade. The green side is fine (200 grit), and used to achieve the sharp edge.
To use, apply gentle pressure, and simply draw the edge of the blade in a 20-degree angle across the stone from the handle to the tip. Repeat this same motion on the other side of the knife.
Immerse the stone in water before use for 10 minutes. Alternatively you can moisten the whetstone with oil, although once you have decided to use oil, you must no longer moisten it with water.
Always place the stone on a flat surface make sure it is secure before sharpening. use the whole surface of the stone when sharpening to keep it from bowling out.