A gas delivery conduit adapted for fluidly connecting to a respiratory gases delivery system in a high flow therapy system. In one embodiment, a nasal cannula includes a base portion defining a first therapeutic gas passageway, a nozzle disposed adjacent the base portion and defining a second therapeutic gas passageway, the first passageway being in gaseous communication with the second passageway and a conduit configured to facilitate sensing that has an inlet side that is independent of and axially spaced apart from an outlet side of the nozzle. The conduit inlet side can extend beyond the nozzle outlet side of the nasal cannula. Additionally, the nasal cannula has a feature adapted to prevent one of the conduit and the nozzle from creating a seal with a user's rare and a feature adapted to prevent one of the conduit and the nozzle from creating a seal with a user's nare.