My first one was installed by my HVAC contractor in my new home. His choice and selection and i an pleased with it. My home has a PTAC in an over garage bonus room as it's only heat and cooling source. It eas installed by myself and thermostat wire was installed also during construction. I purchased a 2nd WiFi 9000 and installed in this room so I can remotly control heat and AC if the room becomes occupied usually by grand children when they are visiting. Install was straight forward and it works great controling the single stage AC and dual stage heat pump/electric heat functions of the PTAC. I did manage to break one if the wire tabs off. I wish they were more robust but unless I ever remove it isn't an issue.