2 pieces adapters set for direct refueling gas bottles. Adapter for direct refueling G 3/4 UNF at 21.8. G 3/4 UNF connections are usually on refillable gas cylinders with 80% fill stop and fuel gauge. The adapter is screwed onto the filling hose connection of the gas bottle and, thanks to its W21.8mm outlet thread, allows Europe-wide direct refueling at filling stations with extra adapters for Europe..
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