The Servonaut king pins are accessories for trailer electronics and semi-trailer electronics AMO.The bolts are drilled through and fitted with brass brackets in which the IR receiver module is simply clicked in. On the side of the tractor unit, the transmitter diode is installed in a way that it shines through the drill when the king pin is locked. That is why the infrared connection between the tractor unit and the semi-trailer electronics is protected from extraneous light and does not disturb other vehicles. The IR connection inevitably tears off with the disconnection of the semi-trailer. This way, the rear lights turn off automatically when undocked.