Aquarium CO2 stainless steel check valve

Product specifications:
Item: CO2 check valve
Material: Stainless steel
Inlet/outlet pipe diameter: 4mm in diameter

Note: Only applicable to CO2 systems! Please do not use this CO2 check valve with an air pump air compressor. The carbon dioxide
check valve is only suitable for carbon dioxide equipment-oxygen cylinders

It can only be used for high-pressure vessels, such as CO2 gas cylinders.
Do not use DIY and air pumps. They cannot be used due to insufficient pressure.