We are happy to offer this replacement thermocouple for the Quest roaster. It's heavy duty and made to withstand the heat your Quest puts out. It's just a thermocouple which means that you will need to supply your own digital thermometer.
Total length of K Type probe is 14cm, sensor is M8 thread, diameter 1.6cm,
about 5.2cm inside QUEST and you may deduct 0.7cm (the thickness of front plate) = 4.5cm