Station Outlets (US) or Terminal Units (ISO, CSA) consist of an outlet port with color-coded faceplate attached to a medical gas supply line, and primary and secondary check valves which open and close automatically upon use and disengagement from the system.[1][2][3] In most jurisdictions, Station Outlets are required to be equipped with safety systems that prevent cross-connection errors, such as connecting a Medical air flowmeter to an Oxygen port. Hospitals mainly use DISS connections, though a wide variety of quick-connect adapters, based on male strikers and female outlet ports, are still in use today. These latter types are easier to connect, but are more prone to leaks and failure.