Hal wrote:

Another question is if you use the M&H O2 and you are staying below
24k do you use the cannula or the face mask? I think I know the legal
answer but it seems that the cannula is actually the preferred option.

The best way to check you and your system under actual conditions is
with a pulse oximeter. Read the article in the recent Soaring magazine,
and borrow or buy one. People do vary a lot, and what works fine for me
might not for you.

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA