Ambient Weather WS-09 8-Channel Wireless Refrigerator/Freezer Thermometer Alarm Set Simple to read, simple to use, and affordable, the WS-09 includes a thermometer in the console and can remotely read and update up to eight remote thermometer sensors at the same from the large digit, uncluttered display. Ideal for Refrigerator / Freezer applications but useful for other temperature applications, the WS-09 includes a display with programmable audible and visual alerts when temperature limits are exceeded. The remote sensors include two water proof probes for measuring any temperature medium, including refrigerators, freezers, water and soil. If your refrigerator is metal, wireless signals can not escape (metal acts as a radio-frequency shield). Thus, the transmitters can be placed outside of the refrigerator / freezer for unobstructed wireless communication to the console. The remote sensors include suction cups to attach to any smooth surface.