ecobee4 Smart Thermostat w/ Alexa (Open Box)

My house was built in the 60s, the HVAC is about 20 years old... I bought this to help maintain better temperature in the home and better regulate the older system... It works fantastic. It comes with the adapter to hook up an older system... it plugs in just right, super easy... And it maintains the temperature in our home much better... We get 2 total sensors in the package (the thermostat has a built-in one) and the extra one... and we bought 2 more of the Room Sensors (updated) and they link up to the system just fine. I recommend between 3 and 4 total sensors, on each floor, to give the system the best chance of working properly with this system. It is saving me money, nearly paying for the thermostat and sensors... by the end of summer, it will have paid for itself. That is a bonus, because next year, it will save me money. Alexa integration works flawlessly...