A cushion member (10) for use in a pressure support system (2) for delivering a flow of breathing gas to an airway of a patient, the cushion member comprising:—；a body portion (12) comprising a first end (14) and a second end (16) disposed opposite the first end, the body portion defining a passage (18) therethrough； and—；a sealing portion (20) structured to sealingly engage about the airway of the patient, the sealing portion extending radially inwardly from the first end to an edge portion (22), the sealing portion having a notched portion (30) defined therein which extends outward from the edge portion.
