PROFESSIONAL "S" are the classic knives for the professional kitchen. The knives are made of proprietary special formula steel that has been perfected over the years. Combined with ZWILLING's signature icehardening technique, these FRIODUR blades are harder, sharper, they will NOT STAIN or chip and they retain their sharpness longer.Honed and handfinished by the most skilled artisans, the knives' lasercontrolled edge is incredibly sharp. The sturdy bolster provides the right balance and acts as a finger guard. Precisionforged from a single piece of solid steel, these threerivet handle knives deliver optimum balance and safe handling. Professional chefs worldwide trust the tradition and quality of these impressive knives.