Adult Non-Rebreather Oxygen Mask (Full Non-rebreather) AKA NRB, Individual mask Medsource International

I am using it for EWOT, exercise with oxygen training. It was built for sick people who don't breathe very fast. At times I am breathing 15 times more volume per minute that someone laying down doing basically nothing. So, no, the mask did not meet my hopes, but I should have had expectations that matched it's design purposes.