Those kettles and stoves are made of Shani clay rugged in Chaozhou. Due to the nature of clay, those kettles are able to soften the water to improve the taste of the tea. The thin-walled character allows them to be lightweight enough to hold comfortably, representing an excellent wheel-throwing skill. Inside glazed: No Filter: a multi-hole filter A: Volume: 500ml Dimension:L=17cm, ∅=13cm, H= 10cm B: Volume: 600ml Dimension:L=18cm, ∅=14cm, H= 10cm Note: the electrical stove works in a range of 20-500w with a guaranteed time of a year. The stove will be automatically turned off every 20 mins during which the swift is not working anymore.