The Ambient Weather TX-3107 floating pool & spa thermometer is ideal for home owners that wish to monitor and send alert notifications when the pool or spa is too hot or cold. It measures water temperature with a 915 MHz wireless range of 150 feet line of sight (100 feet under most conditions). The waterproof sensor both displays the water temperature and wirelessly transmits it to the display console. Add up to 7 floating thermometers to your Ambient Weather WS-8482, WS-8478A, WS-7078, and WS-7079 weather stations. This sensor is not intended for stand alone use. <br><br> The sensor supports up to 7 channels and transmits this information to the display console of your choice, or our cloud service AmbientWeather.net. The information can then be accessed through the console, online dashboard, Amazon Alexa, Google Home, IFTTT, and much more. You can send email, text or IFTTT alerts when watering is required. <br><br> <b>NOTE:<b> The screw-on lid with locking key design with double internal gaskets provide a leak free, water resistant design. TX-3107 is designed to float. If the TX-3107 is used under a cover and the sensor is constantly submerged, the additional pressure will lead to premature gasket failure. Moisture will enter the sensor compartment and cause sensor failure