This sauna has negative ION heater that is tourmaline and 3 mica heating elements which provide directional form of heating. It has a foldable chair and foot massager for relaxing, foot massager can help you sweat away toxin and fat. It comes with digital thermostat. The BTU output is 3000 with 0.7 sq ft coverage per hour. The transfer of heat in this sauna is convectional.