A patient interface has a frame with an opening to receive pressurized gas; a cushion permanently co-molded to frame and defining a breathing chamber; an elbow assembly releasably snap-fittable to the frame with an audible click signaling secure attachment between the elbow assembly and the frame, the elbow assembly including a rotatable swivel elbow; headgear to support the patient interface on the patient's head; and a plurality of gas washout holes to allow escape of CO2 from the breathing chamber.