Ordinary thermostats only read the temperature in one room, but are supposed to deliver comfort in all rooms. Ecobee3 remote sensors deliver the right temperature in the rooms that matter most. Now homekit enabled. Ecobee3 sensors know which rooms are occupied to deliver the right temperature in the right places. And they know whether someone's home to help you save energy and money when you're away. Ecobee3 comes with 1 free remote sensor that measures temperature and occupancy. You can have up to 32 sensors. The more you add, the smarter your Ecobee3 becomes at delivering comfort where it matters and savings where it counts.