After I purchased the gourmet chef's knives from WMF some time ago and this after long use no longer showed the desired sharpness, I opted for the matching knife sharpener. The tool has two slots for coarse roughing and finishing touches. Taking into the instructions and pulls the knife straight through the slots is achieved perfect results. My chef's knife has now again the same sharpness as when buying. Not for nothing the knife sharpener's winner Warentest in its class at Stiftung. Important to know: the sharpener is not suitable for corrugated and serrated knives, and scissors.
