5 adapters set including very sturdy case

Adapters set for direct refueling  3/4 UNF at 21.8mm R.H,

3/4 UNF connections are usually on refillable gas cylinders with 80% fill stop and fuel gauge.

The adapter is screwed onto filling  connection of the gas bottle and, W21.8mm outlet thread, allows Europe direct refueling at filling stations.