This thermostat is specifically designed for the swimming pool, the thermostat is installed in the pool. When adding hot water bath, start the pump, the thermostat automatically heat insulation work, so the water temperature maintained at 42°C, give your pool to create a more Comfortable environment. Ultra-high temperature protection switch and reset button: Ultra-high temperature (over60 °C), ultra-high temperature switch will automatically trip (power off). More detailed descriptions of the product can refer to the instructions