JBL ProFlora CO2 Regulator Advanced is a very high quality CO2 regulator for all common CO2 disposable and refillable cylinders. The regulator has two pressure gauges that reliably and accurately indicate the cylinder pressure and the working pressure. The practical knurled screw allows the pressure reducer to be mounted on the CO2 cylinder without tools. This only needs to be hand-tightened and seals reliably.A conversion to disposable or refillable CO2 pressurised gas cylinders is possible by removing the thread adapter. The CO2 control valve can therefore be used for both types of CO2 cylinders commonly used in aquaristics.JBL ProFlora CO2 Regulator Advanced+ pressure reducer with gauges for disposable and refillabe CO2 cylinders+ gauges for working pressure and cylinder pressure+ usable for CO2 refillable pressure cylinders with thread W21,8 x 1/14(JBL System M)+ usable for CO2 disposable pressure cylinders with thread M10 x 1 (JBL System U)+ fine needle valve for safe and target