A mask for delivery of oxygen to a patient is disclosed, including a body having a peripheral portion, a central portion, and bridge portions extending between the central portion and the peripheral portion. The central portion has an inner surface and an outer surface, the inner surface to be oriented towards the patients face when the mask is in position, the inner surface of the central portion being provided with a wall circumscribing a base. The wall and base circumscribe a centrally positioned oxygen delivery aperture or oxygen diffuser to direct the flow of oxygen generally towards the patients nose and mouth when the mask is in use. An element associated with the aperture and the central portion releasably receives and secures in position an oxygen delivery tube.