The Zwilling 4-stage Hand-Held Knife Sharpener features a German-engineered design that utilizes course and fine ceramic grits to let you manually maintain the sharp cutting edge of Western and Asian-style knives. Anti-slip feet help secure the sharpener in place while gliding the knives through. The Coarse stage is designed to sharpen the blade and the Fine stage hones and polishes for scalpel-like sharpness. Simply place the sharpener on a flat surface and hold the knife in your dominant hand and the sharpener in the other. Insert knife perpendicular to the sharpener into the Coarse stage. Using moderate pressure, pull the knife through the slot from the heel to the tip. Repeat this action as necessary up to 20 times depending on the dullness of the blade. Move the blade to the Fine stage and using light pressure, pull the knife through the slot from heel to the tip. Repeat this action 5-10 times.