Complex sentence: The machines used by oxygen bars or oxygen vendors are different from the typical medical-issue machine, though customers use the cannula, the rubber tube apparatus that fits around the ears and inserts in the nostrils, to breathe in the oxygen.
Split into simpler sentences: The machines used by oxygen bars or oxygen vendors are different from the typical medical-issue machines customers use. The rubber tube apparatus fits around the ears and inserts in the nostrils, to breathe in the oxygen.