Disclosed is a CPAP patient respiratory interface for sleep apnoea to provide breathable gas or air to a patient with an improved fit to the patient’s face. The interface comprises a plenum chamber assembly with a nasal plenum chamber at least partly defining a first gas chamber that is adapted to seal against the patient below the bridge of the nose and around an inferior periphery of the patient’s nose； and an oral plenum chamber at least partly defining a second gas chamber operatively connected to the nasal plenum chamber； and a unitary plate member having an upper portion releasably attachable to the nasal plenum chamber and a lower portion releasably attachable to the oral plenum chamber. The upper portion of the plate member includes at least one connection feature configured to releasably retain a first portion of a positioning and stabilising structure having a pair of rigidiser arms, and the lower portion of the plate member is configured to releasably retain a second portion of the positioning and stabilising structure. The plenum chamber assembly has a decoupling structure at least partly connecting the nasal plenum chamber and the oral plenum chamber, the decoupling structure at least partly defining a flow path between the nasal plenum chamber and the oral plenum chamber.
