ACC0400 - Indoor/Outdoor Sensor for Platinum Slimline Thermostats
Indoor/Outdoor Sensor for the T1700*, T1800, T1900, T2700*, T2800, and T2900
thermostats allows you to see the outdoor temp from the convenience of
your thermostat display! In compatible models the thermostat will track
the high and low temps of the day from midnight to midnight.
Note: * the T1700 and T2700 models are not compatible with the high and low temperature tracking feature.