A sealing cushion 16 for a respiratory mask assembly, the sealing cushion 16 comprising a patient interface portion 18 having a resiliently deformable membrane 24 for engagement with a patients face, and an aperture 26 formed therein for receiving a nasal and/or mouth region of a patients face, wherein an inner surface of the membrane comprises a plurality of projections 45, the projections 45 being arranged such that each projection 45 is engageable with an adjacent projection 45 on deformation of the membrane 24 during engagement of the membrane with the patients face, in use, thereby providing the membrane 24 with an increased resistance to deformation in the deformed configuration. In another aspect the mask includes headgear with flexible straps and first and second fasteners. In another aspect the a mask shell has a retaining formation adapted to support a pair of glasses.
