This is a high quality fitting made by CM Becker in Germany.
Red and grey quick disconnects are used for the gas in tank plug.
1/4 inch male flare (MFL) threaded fittings make it easy to connect a variety of hardware pieces and connectors. MFL fittings are more versatile than barbed fitting, but they must be tightened down properly or they can leak. Barbed fittings are also available.