Tefal Ultimate Non Stick Wok 28cm The Tefal Ultimate Non Stick Wok is a great addition to your cookware collection. It has an extremely resilient non-stick coating, which is 100% safe and free from PFOA, lead and cadmium. The titanium particles in the surface provide added strength and durability while the induction base provides fast and even heat distribution. Never quite know when your pan has reached its optimal temperature? The Thermo-Signal technology in the centre of the pan will change colour, telling you when it's time to start cooking.