This Thermocouple (called a 'K' type) is a simple piece of standard thermocouple cable, high temperature glass insulated, 200mm long, with the 2 cores welded together at the tip. In the 'K' type thermocouple, the 2 metals are copper & constantan and when the junction between 2 different metals is heated, a small voltage is produced which is proportional with the temperature. This small voltage can be used with a controller to accurately control temperature.