A very handy device. Do not use on expensive craft knives. Works best with knives and knives intended as tools, which are not bothered even by a slight damage, as the sharpening angle in this sharpener is not the same as most knives originally. Nor, of course, does the sharpening mark correspond to the craft mark of a skilled sharpener.
Works at least on a kitchen knife really well. Quick and easy to use.