A device that is a component of a medical gas pipeline system or a medical gas/vacuum pipeline system that has a gas-specific outlet connection for oxygen (O2). It is designed to be mounted to wall-mounted medical supply units, utility supply systems (ceiling pendants), or directly to a wall, and functions as the outlet assembly of a gas pipeline system to which the operator can connect and disconnect a device, typically anaesthesia systems, ventilators, respiratory devices, infant incubators, and other devices that require O2 to function as intended. On disconnection of the medical device from the outlet, it will self seal the gas pipeline system preventing gas leakage to the environment.