Patient interface

A patient interface for delivery of a flow of air to a patient, the patient interface comprising:

• a plenum chamber configured to receive the flow of air;
• a prong for delivering the flow of air from the plenum chamber into a naris of the patient;
• and;
• a frame coupled to the plenum chamber, the frame adapted to engage a head of the patient in use for locating the plenum chamber with respect to the naris of the patient;
• wherein the patient interface includes a recess between the frame and the plenum chamber;
• wherein the patient interface is constructed and/or arranged to allow a central portion of the plenum chamber to in use be moved into the recess;
• and
• wherein the patient interface is constructed and/or arranged to allow an end of the plenum chamber to in use be translationally fixed relative to the recess.