A plug-in connection for the transmission of electric current having a male connector and a female connector, wherein the male connector includes a plug-in extension having electrical contacts, and the female connector includes a plug-in extension receptacle having electrical mating contacts, and at least one projection is arranged on one jacket wall, and the other of these jacket walls incorporates at least one receptacle slot which matches the projection. The plug-in extension, with the projection and the receptacle slot in an undamaged state, can only be inserted into the plug-in extension receptacle from an unambiguously defined plug-in position. The male connector, in the plug-in extension interior, additionally incorporates at least one moulding, and the female connector, in the plug-in extension receptacle interior, additionally incorporates at least one mating moulding, and the moulding and the mating moulding, in combination, constitute a stop mechanism for the prevention of any electrical contacting of the electrical contacts with the electrical mating contacts.