SLM is an industrial IoT device with a hydrostatic level sensor. It is specifically designed to measure the water level in wells, pools and reservoirs, and its IP68-rated housing allows it to be used in extreme conditions. The SLM offers accurate and cost effective water level measurement even in places where there is no power supply or where traditional GSM-based technology does not work. It runs on an internal battery and sends data to a dedicated server via LoRaWAN or NB-IoT radio communication. Its built-in antenna can be extended with a cable if necessary, providing a stable connection even in hard-to-reach places.