... invalidation Second:The TYPICAL APPLICATIONS of the ptc thermistor for heating1.air heating,wind warming equipment,cold and warm ... .3.mosquito driving apparatus,boiled water equipment,heating board,shoe drying apparatus,hair curling equipment Third:PTC HEATING CHIPS ... devices,facial sauna,humidifier tec. 2)Tube heating elements for curing irons,wax warmer,glue gun,dehumidifier tec3)other shapes ...