An interface for positive pressure therapy includes a mask assembly, a headgear assembly and a connection port assembly. The mask assembly comprises a seal member that has an upper portion movably connected to an integrated lower portion, wherein the upper portion rolls during hinging movement of the upper portion relative to the lower portion. The headgear assembly allows connection to the mask assembly in a direction substantially normal to a direction of strap tension. The connection port assembly includes a swivel elbow with a valve member that controls flow through a port that opens toward the user. The valve member is provided with a tapered bead that helps prevent the valve member from sticking in a given position. Also, a connector for connecting a respiratory tube to an elbow connector.
