ISO 12209:2013 specifies the characteristics of outlet connections for gas cylinder valves for compressed breathable air gas cylinders. It states the fundamental requirements for both; the connection and its components and includes basic dimensions. Included in ISO 12209:2013 the following connections: a) yoke type outlet connection for SCUBA use up to a maximum cylinder working pressure of 232 bar; b) threaded type outlet connections up to a maximum cylinder working pressure of 232 bar and 300 bar; and c) threaded type outlet connection for SCUBA use up to a maximum cylinder working pressure of 232 bar including adaptor for users to convert into a yoke type outlet. Annex A gives the outlet connection type test procedures. Requirements for cylinder valves (see ISO 10297) are not covered by ISO 12209:2013. Requirements for material specifications and gas/material compatibility (see ISO 11114‑1 and ISO 11114‑2) are not covered by ISO 12209:2013.