Portable Far Infrared Sauna with Heating Panels and Foot Massager - X-Large ABS+PBT material automatic carbonizing to prevent combustion process. It combined with the design of separating the heater from the shell, still comfortable after continuous heating. PTC self-adjusting heating element produces high heating power, fast heating in 3 seconds. 2 level wind speed that you could choose cool or hot! Once the heater fall down or overheating, the heater will stop heating to protect the PTC ceramic heating film and inner part, especially you and your family, your friends.