IRC relay couplers and MFR-IRCP timing relays embody a new concept of coupling relays in a 6.2 mm design. The five different relay versions optimise space requirements, installation effort, user-friendliness and functionality. The interchangeable mechanical relays or optocouplers (SSR) enable customisation to a wide range of requirements. The different coloured cross-connection combs reduce the installation effort. The basic version of the IRC is the familiar coupling relay, which can be used universally in all systems.