O2 Union 6 to 4 mm I, one-touch€ 7,00 One-Touch (Push-to-Connect), 4 x 6 mm, I union. In stock (can be backordered) O2 Union 6 to 4 mm I, one-touch quantity Add to basket Categories: Adapters & parts, Oxygen Description Description O2 Union 4 x 6 mm I, one-touch. To connect the smaller 4 mm air tube to the wider 6 mm tube. Related products Oxygen/Adapters & partsRegulator Fitting one touch 4mm – 180º € 15,00 Add to basket Oxygen/Oxygen bagsO2 cylinder bag – black € 69,00 Add to basket Oxygen/Adapters & partsRegulator Fitting one touch 4mm – 90º € 15,00 Add to basket