Specification :

To extend the life of your Samurai Shark,occasionally change the grinding area of the tungsten-carbide sharpeners.This is achieved by turning the smaller blue dial for the front sharpeners and turning the larger blue dial to loosen the sliding rear sharpener.
It's best to hold your Samurai Shark on an angle while using it in your hand.The tungsten-carbide sharpeners only sharpen on the edges,not the flat surfaces.Having it on an angle ensures your blade will be properly sharpened.
try not to use too much pressure when sharpening.Although some pressure is needed,too much pressure can lessen the life of a blade.You should hear a steady,grinding sound when you have the right amount of pressure.