The CRAZEDpilot OxySaver Oxymizer Pendant Cannula for Aviation Oxygen systems will prolong your oxygen cylinder service time by up to 75%! This is thanks to the integrated manifold which reduces oxygen flow by retaining and ‘mixing’ the oxygen between each breath (as opposed to being lost into the atmosphere when you aren’t breathing it!) It is easy to use and so light-weight, you can drink, eat or talk with it comfortably in flight. The design is simple and compatible with ALL aviation and non-aviation applications! NO RETURNS DUE TO SANITARY NATURE OF THIS ITEM.