Wusthof’s Asian-Style Hand-Held Knife Sharpener has two notches designed to sharpen Asian style knives at a 10° angle. The first notch is carbide (coarse) for sharpening dull edges. The second notch is ceramic (fine) for providing a polished, razor sharp edge. Simply place the sharpener on a flat surface and, providing slight pressure, pull the blade through the appropriate notch as many times as necessary. A reasonably sharp blade may only require honing through the ceramic notch.