The ACK Long Life Thermocouple is a sensor for measuring the temperature of the wok cooker. It is made up of two wires of different metals that, when joined together, create an electrical junction. When the temperature changes at this junction it creates a voltage which can be interpreted to read the temperature by a thermometer connected at one end.
This long life thermocouple with 9mm lock nut, 300mm length can provide temperature measurements over wide range of temperatures.