DEVICE: Expiratory valve set (07630002802734)

A non-sterile mechanical device intended to be used in a respiratory or anaesthesia breathing circuit or system to maintain a degree of positive pressure in a patient's airway at the end of expiration. Typically constructed of plastic/metal it has a valve that is actuated by a spring to provide expiratory airway resistance, and an adjustable knob (usually not graduated) that is typically set between 0 and 20 cmH20 pressure, but may be fully closed when controlled/assisted ventilation is applied. It is normally used with anaesthesia breathing systems, pulmonary resuscitators, or ventilators and is commonly known as a pop-off valve, relief valve, or spill valve. This is a single-use device.