The battery-powered ultrasonic flow meters FLOMIC FL503X (single beam) and FL505X (dual beam) are intended for measurements of instantaneous flow rate, pressure and water consumption in piping in observance of standard EN 14154 in water works, water distribution systems and other industrial applications. These flow meters are of a compact or remote design with the IP 68 protection class. They are characterised by high measurement accuracy and long-term stability over a wide range of measured values. The meters do not need any external power supply, they are battery supplied with live time of battery four years with sampling of measurement of flow one second. They do not include any moving parts and, have significantly lower hydraulic losses. The technical parameters and other features of the FLOMIC flow meters make them suitable not only for water consumption measurements, but also for water-leak tracking and monitoring of the general condition of water-supply networks, where the meter output signals can be connected via data transfer systems to remote computer control stations. In the standard version, the meter measures instantaneous flow rate (in mV/hour) and the total volume of water passed through the meter (in m3) in the given flow direction. The measured data are converted into pasive electrical outputs and can be transvered via optically insulated USB or RS 232 interface through GSM communication to a remote control system.