This knife sharpener automatically adjusts to suit all plain-edged knives. It is suitable for all European & Japanese edge profiles. Not the sharpest knife in the drawer? I’ll soon see to that! My tungsten-carbide sharpening tools are engineered to automatically align themselves to suit the edge angle of all plain-edged knives, even asymmetrically ground Japanese knives. What’s more, they are specially shaped to allow resharpening of dull blades & honing of sharp ones depending on how you hold the knife in the sharpener. This has stood the test of time through an unrelenting dedication to quality, service and good old fashioned technical know-how in the design and production of kitchen knives and scissors. It is uniquely shaped 2 stages tungsten-carbide mechanism re-edges blunt knives & hones your knives to keep them sharp. The honing of a blade gently straightens any microscopic kinks & bumps in the edge that occur during day-to-day use. regular honing keeps a sharp knife sharper for longer. To hone a freshly sharpened edge & for regular maintenance of your knives, gently pull the knife through from heel to tip 3-5 times, with the blade tip pointing upwards.