A mask for the delivery of a medical gas under positive pressure, the mask including a single shell forming a chamber having an outlet, a first passage connecting the chamber to the exterior of the mask, a sealing recess isolated from the chamber and open to allow engagement with the face of a user, and extending around the periphery of the outlet, and a second passage connecting the sealing recess to the exterior of the mask, the arrangement being such that operatively the mask may be placed on a user so as to cover the airway, suction may be connected to the second passage so that the sealing recess seals the mask against the face of the user, and a medical gas may be supplied to the first passage for delivery through the outlet to the airway of the user.
