CO2 Controller (Air Tighten). Easy assembling: no tools required for attaching to the CO2 cylinder.
CO2 Regulator - Controller Features: Easy assembling: no tools required for attaching to the CO2 cylinder. Extremely precise needle valve assures accuracy and reliability in dosing the CO2. Strict quality control assures the best quality. Safety valve prevents any accidents if overpressure occurs. Two gauges: one shows the internal pressure (amount of CO2) the other shows the released pressure to the aquarium.