Safety in a proven design. The Zwilling Four Star series is the best-selling Zwilling knife series worldwide and features a seamless full plastic handle that sets high standards for kitchen knives. Handle material: plastic, seamless transition from bolster to handle, stainless special steel, Zwilling special melt, Friodur blade, ice-hardened, Sigmaforge knives – forged from a single piece for precise cutting. Hand washing is recommended.