Spa-Tech Plastic Temp Sensor.
Commonly found on the Spa-Tech C-III heater elements.
This plastic nut sensor can be used as a replacement for the older 9.5mm diameter thread metal sensors.
"Best replaced as a pair"
This Sensor has undergone a change end of 2018 to a plastic nut / SS thermowell.
this new design fits the same thread as the original TS2 100% SS design shown
Suits a lot of Galaxy Spas