Zwilling Twinsharp Select Sharpener: Sharperning knives with this innovative knife sharpner and its two different sharpening modules is easy and efficient. Clear instructions make it easy to use because, in contrast to a sharpening steel, the angle is clearly preset. It is nearly impossible to use this sharpner the wrong way. The disc module (1) restores the angle of the edge. Module (2) subsequently evens the edge and restores the required sharpness. Additionally 'Twinsharp Select@ can be used by both left and right handers. Only a few pulls with little pressure through bothmodules will re-sharpen knives easily and safely. Not suitable for Asian style knives