The Smart Senor acts as additional temperature sensors around your house to allow for full house control of the temperature. I have placed one of these upstairs, and one downstairs in our house. There was a 10-12 degree difference before I installed my Ecobee with the additional Smart Sensors. Now, there is 3-4 degree difference in our house between all floors. I also have been using the Smart Sensors as motion sensors in SmartThings to trigger automations.