It is O2, but it's not designed for people with COPD who need supplemental O2 to function properly. It's designed for athletes and people who may put out really short bursts of intense effort, and frankly, I don't think it's worth much, even for them. It's been around for several years and does sell, but it's not something that people with COPD should be considering as it really doesn't meet our needs at all. Spend your time and energy in the gym rather than on this stuff; you'll get a much bigger bang for your buck!