Abstract: A medical circuit comprising a medical tube and a connector transports gases to and/or from a patient via a patient interface. The connector has a plurality of rigid components at least partially surrounded by an overmold. The medical tube has a first elongate member and a second elongate member. The first elongate member is substantially hollow. A vent can be coupled to the first elongate member such that it maintains gaseous communication with the lumen. The vent may provide a pathway between the lumen and the atmosphere, such that gases may move into and/or out of the lumen during cleaning. The vent may also provide a barrier to liquid and/or substance ingress into the first elongate member during cleaning of the medical circuit. The medical circuit can be reusable.