Defective out of the box. The thermostat didn't turn on the fans. Turn on the green wire, there are still no fans. Switch 12V directly to run fan.fans. The product fit and installed well until I had to take it off and replace it with another brand. In addition, the temperature adjustment screw is so small that you cannot adjust it when installed vertically. Very disappointed, the derale fans work so well but the controller sucks. Derale customer service told me they had all gone out for lunch 2 times when I called. Not healthy