A device for treating sleep disordered breathing. The device has a vent system (350) constructed and arranged to utilise a selected vent of a plurality of vents (352, 354). A sensor (353, 355) is configured to detect a characteristic of the selected vent in use (354) and send a signal (356) to a flow generator (358) or blower controller. The signal is used to adjust a control algorithm of the flow generator or blower controller in response to the characteristic of the selected vent tailoring the operation of the flow generator or blower controller to the vent selected.
