How many pulse flow settings does the GCE Zen-O accommodate? You are here: Main Portable Concentrator FAQs GCE Zen-O GCE Zen-O FAQs How many pulse flow settings does the GCE Zen-O accommodate? < All Topics The GCE Zen-O has six flow settings, from 1 to 6. 1 being the lowest and 6 being the highest.