A coaxial connector system comprises a coaxial plug connector and socket connector. For one embodiment, low profile bus bars are used between the IMS PCB and a fiberglass PCB. , and it is possible to achieve excellent maintainability. A gas-permeable thin film resin member is bonded to an inlet of the air path. The forces exerted by the pressure of the gas on the main portions of a turn of the duct are then compensated by the forces exerted on the adjacent turns of the duct. The mounting hole has the shape of a keyhole, and so the fixing piece inserted into it, which may also comprise two latch plates placed at a distant from each other thus forming a fixing groove, is locked into the slit-shaped part of said mounting hole.