The invention relates to a connection device for transmitting electric current, in particular for a steering wheel heater of a motor vehicle, between a stationary housing part and a rotor which can rotate with respect to the housing part, comprising a flat ribbon cable and end plug connectors which are provided in the region of the free ends of the flat ribbon cable. The invention is characterized in that the flat ribbon cable has a central plug connector which is placed between the end plug connectors and is intended to be arranged on the rotor side or housing side, from which central plug connector at least one line runs to one end plug connector and to the other end plug connector in each case, wherein the two end plug connectors are intended to be arranged on the housing side or rotorside. The invention also relates to a steering column/steering wheel transmission unit with a connection apparatus of this type.