ChefMaster's knife sharpener is pre set to sharpen at the proper angle every time. Average sharpening time of 10 seconds. Great for chef's knives, serrated knives, fillet knives, slicers, cleavers, pizza knives, butcher knives and more. Diamond honed tungsten carbide sharpening blades. Tough polypropylene full finger guard. Dishwasher safe. Lifetime warranty.