T9 T10 Old Version Room SensorSense the temperature in any room The T9 T10 Room Sensor work with the Honeywell Home T9 and T10 Smart Thermostats sensors help provide temperature control by focusing on the important rooms in your home. The sensors have a 200 foot range that detects indoor temperature, humidity and motion and transmits back to the thermostat to deliver reliable, whole home comfort. Add up to 20 Smart Room Sensors to your T9 or T10 system and prioritize heating and