Professional Santoku Knives Set of Two 7 inch (17.7 cm) Blades are made of Stain-Free High-Carbon Steel Handles with Antimicrobial Protection. Polypropylene Handles have built-in microbial product protection., which inhibits odor and stain-causing bacteria, mold and mildew. Although this protection is good for the life of the knives, it does not protect against foodborne bacteria. Always clean knives thoroughly after each use. Dishwasher Safe. NSF International Compliant.