FOUR STAR is the topselling knife series of ZWILLING J.A. Henckels worldwide. Honed and handfinished 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 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. Precisionforged from a single piece of steel, the SIGMAFORGE knives have an exceptionally sturdy, balanced and flexible blade.