The Air Temperature Sensor measures indoor or outdoor air temperature with a range of -20 to 120 degrees F. If used indoor as a remote temperature sensor, the sensor will read room temperature and send the information to the thermostat. If used as an outdoor temperature sensor, the sensor may be used to provide outdoor temperature information (which is not used to control heating or cooling). The sensor should be mounted out of direct sunlight and in a place that is protected from direct rain and snow. Mounting the sensor under an eave of a roof or under an overhang of a building is recommended. Use 18 – 22 gauge 2 conductor unshielded thermostat wire. Wire length should not exceed 200 feet.