These knives are made of high quality stainless steel and feature stylish stainless steel handles. Easily sharpened and holds their edge well. The knife is and low temperature resistant and safe to use in the freezer. 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° angle from tip to handle over the complete length of the blade. The speed of the process has no impact on the result.