This thermostat can be wired to call for heat or cool. Installed this in a customers greenhouse to control a large fan. The enclosure is made out of thick plastic seemed very strong and durable. It has a 1/2 threaded opening. There are four mounting tabs for screwing it to a flat surface. We'll see how it holds up in greenhouse where the temperatures here in Connecticut can swing radically. I liked the plastic enclosure as it would seems to hold up in a damp environment.