The two-hole flange ball can be adjusted in height if the flange plate on which it is mounted consists of four coupling points rather than two. The two-hole flange ball can then be fitted to both the upper and lower two coupling points of the flange plate. Particularly if you have a delivery van, the height adjustability can be useful. The two-hole flange ball can be adjusted in such a way that the rear doors can always rotate over the drawbar of the trailer. With a flange plate consisting of four coupling points, you can also use other coupling systems (such as the drawbar coupling, the claw coupling and the ball-pin combination). On this flange plate the mentioned coupling systems fit exactly.