This is a undervoltage switch module used to turn off the power of resistive load in the event of the voltage dropping below a definite value.
Default undervoltage protection value is about 10.5V, and can be adjusted by turning potentiometer, clockwise to increase and anticlockwise to reduce.
If the load restores immediately after it is turned off, you can add a capacitor(>25V), and the capacitance depends on your load.
When the voltage rises back, the module will automatically turn on load again.
The module has a low power consumption of less than 10mA.