1 MM CARBON STEEL: the high quality construction means it won't warp, while an electroplated finish prevents rusting. QUANTUM II NON STICK: this powerful double non stick layer releases food easily, cleans up quickly, and is PFOA, PTFE and BPA free. LOOSE BASE: removing baked savoury quiches or fruit tarts and flans is easy with the pop-up loose bottom. USEFUL INFO: this perforated quiche tin measures 23cm; dishwasher safe; includes MasterClass's 20 year guarantee (5 years' non stick).