IEC 61754-27:2013 defines the standard interface dimensions for the type M12-FO family of connectors. This connector is of duplex plug/adaptor/plug configuration and designed for industrial environment as described in ISO/IEC/TR 29106, severity class M3 and I3. Multiple designs for machines and equipment require solutions with different fibre types. Keywords: standard interface dimensions for the type M12-FO family of connectors