Portable Beaver Respirator Wooden case with locks and detachable lid, containing the portable Beaver respirator. The device consists of a wooden unit housing an electric motor, accessible via a side panel with printed instructions and cable. A green-coated metal and rubber bellows is mounted externally on top, and connected to the motor below. The movement from the bellows generates airflow, and directed through a detachable tubing system connected to a metal outlet on the side of the case for the patient circuit. The top panel unit also features expiratory and high-pressure relief valves, and an airway pressure gauge and a on-and-off switch. Made by The British Oxygen Company Limited. 1950-1999