The MX2001-S Water Level Sensor is used with the HOBO Bluetooth Low Energy Water Level Data Logger (MX2001), the HOBO MicroRX Water Level Stations (RX2103 and RX2104), and the HOBO RX3000 Remote Monitoring Station for accurate water pressure, temperature, and water level measurements. These sensors are available in four depth ranges, as well as in stainless steel or titanium (recommended for use in saltwater).