Product review (5 stars): Used for a freezer malfunction alarm
When I was looking for a freezer alarm the devices I found typically were battery operated and had an audible alarm that could not be heard unless you were near by. That was not practical for my freezer located in a detached garage. I have configured this device to be used as a heavy duty alarm. I put the probe in my freezer but plug the device into a separate power outlet. I plug a portable radio turned up to full volume into the controllers relay and turn the temperature setting down to 20 degrees. If the temperature in the freezer exceeds 20 degrees + the offset then the relay powers the loud radio. It is not perfect in that I would like a lower set point, but it will get my attention before the contents of the freezer thaw.