Stainless Steel CO2 check Valve with spring/ CO2 non return valve

Applicable  fpr 4mm air or co2 tube CO2 Check Valve Stainless Steel is used to prevent water back-flow or siphoning down the tubing when the pressure is turned off. If water were to reach your electronic equipment such as your CO2 solenoid, or air pump it can cause it to flood and not operate, or risk electrical fire. This simple item eliminates that possibility by not allowing air or water to flow in the opposite direction to which it is installed.