VEVOR Double Gauge Regulator, CO2 Regulator Gauge with 0-60PSI, Heavy Duty CO2 Gauge Gas System, Draft Beer Regulator with Check Valve, Adjustable Pressure Regulator for Draft Beer Homebrew, CGA320

It is generally used for beer. The filled gas is a mixture of CO2 and N2. Nitrogen is an inert gas, and it does not react with other substances under normal temperature and normal conditions, including that it does not react with aluminum bottles. But you must fill it according to the requirements of the cylinder and meet the pressure of the tank.