Non-rebreather masks are used to deliver oxygen therapy to people who require high-concentration oxygen but aren’t in need of breathing assistance. They’re considered low-flow oxygen delivery systems.

A non-rebreather mask is a medical device that helps deliver oxygen in emergency situations. It consists of a face mask connected to a reservoir bag that’s filled with a high concentration of oxygen.

A non-rebreather mask is a special medical device that helps provide you with oxygen in emergencies. These masks help people who can still breathe on their own but need a lot of extra oxygen.

A doctor has disproved the myth that face masks or coverings lower oxygen levels in a viral video posted to Twitter. Maitiu O Tuathail, a doctor in Dublin, posted the video and said: "Getting asked ...