Always use a high quality steel by BergHOFF for your top quality knives. These sharpening devices are exactly made to match the steel of the blades and guarantee an optimum result. Be sure to maintain a 20 Deg angle from tip to handle over the complete length of the blade. The speed of the process has no impact on the result. Diamond stainless steel knife sharpener Non-skid base secures the sharpener's placement when sharpening knives, ensuring stability. Utilizes diamond plate to smooth and sharpen blades Features three grinding stages: coarse, medium and fine Hand wash with warm water, mild soap and nonabrasive sponge.