FOUR STAR is the top-selling knife series of ZWILLING worldwide. Honed and hand-finished by the most skilled artisans, this celebrated collection is the model of safety, ergonomics, and comfort. Thanks to their seamless transition from bolster to handle, the knives are comfortable to use for long periods of time. The bolster provides the right balance while acting as a safe finger guard. The knives are made of proprietary special formula steel that has been perfected for over 280 years. Combined with ZWILLING's signature ice-hardening technique, these FRIODUR blades are harder, sharper, they will NOT STAIN or chip and they retain their sharpness longer. Precision-forged from a single piece of steel, the SIGMAFORGE knives have an exceptionally sturdy, balanced and flexible blade.