Water Tank Level Threshold Sensor is a long range wireless sensor which can be used for detecting that the Water Tank level is below or above a specific point. You can put the sensor into a water tank(let�s say 5 meters higher than the base) and monitor whether the water level is up or down from the level which sensor states. So it can give information whether there is any water in the tank on this level or not. This sensor is compatible with LPWAN technology by using NB-IoT(Narrowband-IoT). The standard version of this sensor is powered by one replaceable 3.6 V AA sized battery (included with purchase).