Embodiments of the present invention provide a device, system and method for providing high flow therapy interfaces for use in the treatment of respiratory conditions and in assisted respirations. A nasal cannula for delivery of respiratory gases supplied from a respiratory gas delivery system that includes at least one nasal insert that includes a lumen for the supplied respiratory gases from the respiratory gas delivery system, at least one flange coupled to the at least one nasal insert and configured to partially impede the egress of respiratory gasses delivered to an upper airway of a patient, where the flange includes a top surface defining a corresponding top surface area and where the flange further includes at least one slot that defines a corresponding implicit surface area, the top surface area of the top surface being substantially greater than the implicit surface area of the at least one slot is provided.