Patient interfaces

An interface for positive pressure respiratory therapy includes a mask assembly having a mask seal and a mask shell. The mask assembly is positioned lower than and exposes a bridge of the user's nose. The mask seal includes first and second portions on respective first and second sides of a nasal region that contact opposing sides of the user's nose. In some configurations, the first and second portions each include supports that help maintain a shape of the mask seal. A pair of covers can be supported relative to the mask assembly and adjacent a respective one of the first and second portions of the mask seal. The covers limit expansion of the first and second portions of the mask seal in response to pressurized air within the mask seal. The supports of the first and second portions can transfer load from the mask seal to the covers. An interface system can include multiple size mask seals, which can be designed with consideration of ethnic variations in nose size and/or shape.