I often times I get winded when walking with my One G5 set to 4 L/M, as the DR. ordered. MY question for other users is how long in the Blast of air you get from yours last. Mine is one second at the max. I do see how this could possibly deliver 4 L/M. I balled Inogen and they just danced around my question and couldn't answer.
Please comment if you can,
Kevin