Standard High Limit Switch - 36 inch
High limit switches are present to open if your spa thermostat or contactor fails and the water reaches a very high temperature (usually about 120 ° F). By opening the circuit, the heater will be turned off. They can be manually re-set by pressing the red button.
The probe wire comes tightly wound so if you don't require the full 36 inches, simply leave it partially wound up.