The revolution Series 5. 5 Santoku knife is from Kyocera?s most popular line of advanced ceramic knives. Designed with a comfortable ergonomic handle for precise control. The ceramic blades are made from a proprietary zirconia material produced in Japan and stays razor sharp at least 10 times longer than traditional knives making them ideal for everyday use. The perfect choice for slicing fruits vegetables and boneless meats. Not intended for frozen or hard foods. Kyocera advanced Ceramic cutlery and kitchen tools are fully warranted to be free of defects in material and Craftsmanship.