This button is only used when the unit is operating in an unfavorable way or malfunctioning. Use a blunt stylus to hold down the button. All settings will return to their default values. MULTI-CHANNEL CABLE FREE REMOTE THERMO SENSOR MODEL: THC138 Congratulations on purchasing the THC-138 Remote Thermo Sensor. The Remote Thermo Sensor is used with the 433MHz Multi-Channel In-Out Thermometer (Model: EMR812, EMR899, RMR112 or BAR888) to monitor temperature changes of remote or outdoor sites. Operation is easy and no wire installation is required. HOW TO USE THE TABLE STAND OR WALL MOUNT This sensor comes with a wall-mount holder and a removable stand. Use either to set up the unit. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures: · · · · Reorient or relocate the receiving antenna. Increase the separation between the equipment and receiver. Connect the equipment into an outlet on a circuit different from that to which the receiver is connected. Consult the dealer or an experienced radio / TV technician for help. MAIN FEATURES: LCD Displays the current temperature monitored by the remote unit and indicates the selected channel LED INDICATOR Flashes when the remote unit transmits a reading TEMPERATURE SENSOR PROBE On 10 feet (3 meter) cable PRECAUTIONS This product is engineered to give you years of satisfactory service if you handle it carefully...