This document concerns pin-index yoke-type valve connections for medical gas cylinders, with a working pressure up to a maximum of 200 bar and/or test pressure up to a maximum of 300 bar. NOTE – This type of connection is primarily used for small cylinders (5 l or below). It specifies: – basic dimensions; – requirements for alternative designs of the yoke-type valve connections; – dimensions and positions for the holes and pins for the outlet connections. It also specifies the dimensions and positions for the holes and pins for the outlet connections for the gases and gas mixtures given in Table 1.