How to fasten: Attach the pressure regulator to the CO2 cylinder's on/off valve securely. Ensure the CO2 outlet control knob is in the closed position. Connect the CO2 supply hose to the CO2 inlet and secure it firmly. Open the CO2 cylinder's on/off valve, then gradually adjust the pressure regulator's CO2 outlet control knob to the desired CO2 injection rate. How to loosen: Close the CO2 cylinder's on/off valve. Release all remaining CO2 gas until it is completely empty, then detach the Flow Regulator from the CO2 cylinder.