One comment - Absolutely go with using the oxymizer cannula. According to some of my reading you can save 2x to 4x of your O2. Take a look at the two different flow scales on the MH-4 (http://www.mhoxygen.com/portable-con...h4-flowmeters-) The long right hand scale is for a standard cannula and the much shorter right hand scale is for the oxymizer.