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 SaleOxygen/Mountain High EDSMH EDS O2D1 kit € 1.025,00 € 850,00 Select options Oxygen/Cannulas & masksEDS Face Mask € 13,50 Add to basket Oxygen/Oxygen bagsO2 cylinder bag – black € 69,00 Add to basket