Germany
Adapter Air (5/8") -- inert gas (W21.8) inside / inside
Filling adapter for carbonic acid for filling CO2 and argon cylinders with valves according to DIN 477-6 which have a flow-off protection/residual pressure valve. The thread W21.8 is used for all gas cylinder valves that are used for shielding gas welding, argon, helium, carbonic acid and argon mixed gases.