Armstrong Pro Series™ Comfort Sync® A3 thermostat, which allows one to control one's home temperature from smartphones or other mobile devices. Comfort Sync zoning allows even more personalization by dividing one's home into up to four different areas, or zones, each with its own temperature control. Compatible with Amazon Alexa and Google Assistant. Uses the GPS in one's smartphone to detect when one is leaving and automatically changes the temperature to be more energy efficient.