Abstract: 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 said base portion and defining a second therapeutic gas passageway, the first therapeutic gas passageway being in gaseous communication with the second therapeutic gas 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 that is adapted to prevent one of the conduit and the nozzle from creating a seal with a user's nare and a feature that is adapted to prevent one of the conduit and the nozzle from creating a seal with a user's nare.