For measuring the flow and volume of cold water with a temperature up to 30°C or 50°C in the closed-circuit system with the full flow of the flux, and on the maximum working pressure up to 16 bar (PN16). Re commended installation of a prepaid water meter set concerns me tering of water consumption in rented flats, social flats or in holiday cottages i.e. everywhere where the consumer changes very often and there might be a problem to collect the amounts due for water con sumption. Suitable for installation in the horizontal hoses (pipelines) with the counter directed upwards (H) and in vertical or horizontal hoses with the counter directed sidewards (V). Prepaid water meter system consists of: prepaid water meter set (IP68 – JS water meter, stop valve, electronic module), wireless control unit and PC software. The system is intended for settlement of water consumption based on in advance payments for 6-digit codes that allow drawing a definite water volume. When the water volume bought will be used up, the water flow is closed by the valve. The outlet port of stop valve housing is adapted for optional installation of a return valve.