Constant temperature, ceramic shell, compact construction, easy to assemble, sefty, long life, no damage for over temperature Some appliances. wax melting heater,vapor generator,humidifier,water boiler,liquid warmer,coffee warmer,polymer press-coating heater,hot glue gun,chocolate extruder,shoe dryer,hand/foot warmer,massager,physical therapy heater. 1) Aluminum shell. PTC heater is very ...