The frost guard ensures continuous filtration when the temperature is below a specified value.
The device will start (forced) filtration when the air temperature is below the setpoint (adjustable).
This makes the frost guard the ideal addition to any hot tub. The frost guard ensures that the filter pump runs regularly and thus moves the water. This means that it does not freeze in winter, even in frosty temperatures.
This means you can use your hot tub all year round. Or just go on a skiing holiday.