This durable glass lid is made of heat-tempered glass for additional strength. It fits the Swiss Diamond 8 inch (20 cm) Fry Pan. It can also be used as a universal cover for any 20cm cookware, including pots and pans. The handle features a rotating ring that opens and closes the adjustable steam vent - this allows the chef to control moisture in the pan without lifting the cover. The lid, like all Swiss Diamond cookware, is safe for oven use to 260 C (500 F). Do not expose to thermal shock - allow the lid to cool before placing it in water.