Abstract: The present invention provides methods and apparatuses for gas delivery, in particular, a mask including at least one porous barrier defining at least two chambers in gaseous communication. The porous barrier may include a plurality of pores, which define a tapered shape. The mask may include a pliable nasal cushion. The invention provides a method for providing pressurised gas to a subject by supplying gas from a pressurised source to a mask, transmitting the gas into a first chamber at a first pressure, transmitting the gas into a second chamber at a second pressure through a plurality of pores, and transmitting the gas from the second chamber through a mask exit.