I'll call BS on the idiot's post.  Not only do I not profit from O2 I have to pay for my own as I cannot get insurance to cover it most of the time.  I also had to pay for my O2ptimasks (2) and two others I bought for newbies that needed help.  I couldn't get a 25lpm regulator from my med supplier, so he gave me 2 15 lpm regs and we used two M tanks with a Y connector.  Not only can I breath all of the O2 provided in an attack of K7 or higher I'll suck the bag flat and be sucking for air at 30lpm.  This will kill hits within 5-8 mins.  Years ago when I tried using 15 lpm I gave up because I was sucking it down for up to 30 mins at a time or relief.  I quit using it and thought it didn't work because my hits normally last 30-45 mins.

To anybody new to the O2 regimen please pay no attention to this moron.  (I can't call him a troll although he is acting like one).

Jerry