When the DXP was introduced, Swiss Post also ordered new, braked trailers with a payload of 150 kg. The previous trailers were unbraked and approved for 80 kg total weight. To avoid confusion, it was decided to use a different trailer hitch.

KYBURZ developed its own system with the ball on the vehicle. Before approval, the design was extensively tested, including a vibration test. The design appears very solid, but large forces act on the ball of the coupling, which is approved for a towing load of 200 kg, when the trailer is fully loaded.

KYBURZ has a design protection on the trailer coupling. The bracket, which is equipped with a pin, locks the socket attached to the trailer. In addition to new couplings, KYBURZ also offers revised couplings at a reduced price.