After reading Yvette’s note I thought to add a comment on the G5 regarding the pulse.  The G5 tracks when you inhale to initiate a burst of oxygen and it also tracks how frequently you inhale to determine how much oxygen should be in that burst.

If I set it at 5L and breath fast like I am out of breath it will give me short bursts of… Read more

Not sure what you mean by an “active lifestyle” but my definition was giving up playing 18 holes of golf 3 or 4 times a week.  I’m not sure I consider all the units in your list as really portable which I think means easily carried.  I also think that things maintaining an exercise regimen is the most important aspect of trying to keep an active… Read more

I disagree.  I believe the G5 will actually produce 1.2 L of oxygen, not the equivalent of 1.2L.  With a continuous flow of 2L most of the oxygen is wasted since you normally inhale, exhale, pause and repeat the cycle.  The G5 emits a pulse of its 1.2L as it detects you are inhaling and will also try to compensate by changing the amount of… Read more