We have a small 15 x 20 greenhouse with a propane heater that I oversized because we are going to expand it in the future. In hindsight, I should have just gotten a second heater when that time came. We had some issues with the unit short cycling so I bought this thermostat so that I could set a custom diffferntial. It works great and solved our issue.

The device worked as described and was easy to wire up and install. I can't comment on the durability because I haven't had it long enough to let the weather test it out.