This Global superfine 5000 grit ceramic whetstone finely hones a knife edge which extends the length of time it will stay sharp. When sharpening knives, scissors, planes, engraving tools, etc, it's most important to remember to maintain the same angle (degree). This applies whether one is using a ceramic whetstone or a honing rod. Apply a small amount of water to the surface. Then hold the knife so that the blade meets the face of the whetstone at an angle of 10deg-15deg. Sharpening instructions are included.