Connector for transmitting electrical current, having a male plug connector and a female plug connector, wherein the male plug connector has a plug-in extension with a plug-in extension sheath wall and electrical contacts, wherein the electrical contacts are arranged in a plug-in extension interior surrounded by the plug-in extension sheath wall, and the female plug connector has a plug-in extension receptacle with a plug-in extension receptacle sheath wall and electrical mating contacts, wherein the electrical mating contacts are arranged in a plug-in extension receptacle interior surrounded by the plug-in extension receptacle sheath wall, wherein at least one projection is arranged on a sheath wall which is the plug-in extension sheath wall or the plug-in extension receptacle sheath wall, at least one projection is arranged and the other of these sheath walls has at least one receiving slot corresponding to the projection, wherein, in an undamaged state of the projection and the receiving slot, the plug-in extension can be inserted in a plug-in direction into the plug-in extension receptacle exclusively starting from an unambiguous plug-in position predetermined by the projection and the receiving slot, wherein the male plug connector additionally has at least one molded part in the plug-in extension interior and the female plug connector additionally has at least one mating molded part in the plug-in extension receptacle interior, wherein the molded part and the mating molded part together form a blocking device for preventing electrical contact between the electrical contacts and the electrical mating contacts when the plug-in extension is inserted into the plug-in extension receptacle starting from a position deviating from the unambiguous predetermined plug-in position, wherein one part, which is the molded part or the mating molded part, has at least one free space, preferably V-shaped when viewed from above, into which the other of these parts penetrates during insertion of the plug-in extension in the plug-in direction into the plug-in extension receptacle starting from the unambiguous predetermined plug-in position, characterized in that the part penetrating into the free space is rotatable in the free space between two rotary stops. the male plug connector has a plug-in extension with a plug-in extension sheath wall and electrical contacts, wherein the electrical contacts are arranged in a plug-in extension interior surrounded by the plug-in extension sheath wall, and the female plug connector has a plug-in extension receptacle with a plug-in extension receptacle sheath wall and electrical mating contacts, wherein the electrical mating contacts are arranged in a plug-in extension receptacle interior surrounded by the plug-in extension receptacle sheath wall, wherein at least one projection is arranged on a sheath wall which is the plug-in extension sheath wall or the plug-in extension receptacle sheath wall, at least one projection is arranged and the other of these sheath walls has at least one receiving slot corresponding to the projection, wherein, in an undamaged state of the projection and the receiving slot, the plug-in extension can be inserted in a plug-in direction into the plug-in extension receptacle exclusively starting from an unambiguous plug-in position predetermined by the projection and the receiving slot, wherein the male plug connector additionally has at least one molded part in the plug-in extension interior and the female plug connector additionally has at least one mating molded part in the plug-in extension receptacle interior, wherein the molded part and the mating molded part together form a blocking device for preventing electrical contact between the electrical contacts and the electrical mating contacts when the plug-in extension is inserted into the plug-in extension receptacle starting from a position deviating from the unambiguous predetermined plug-in position, wherein one part, which is the molded part or the mating molded part, has at least one free space, preferably V-shaped when viewed from above, into which the other of these parts penetrates during insertion of the plug-in extension in the plug-in direction into the plug-in extension receptacle starting from the unambiguous predetermined plug-in position, characterized in that the part penetrating into the free space is rotatable in the free space between two rotary stops.