The harmonica roller conveyors with plastic wheels or steel rollers can be pulled in and out just like a harmonica. Because the roller conveyor works like a harmonica, it is also possible to make a bend of up to 180 degrees with the roller conveyor. The flexible roller conveyor is supported by several undercarriages and has braked wheels. The frames can be mutually adjusted in height so that the height can be adjusted to the user and, for example, to the working height of a box closer that you can place for this. If this concerns a de Witt box closer, we will supply a coupling plate to the whole with the flexible track as standard brackets easy to connect and disconnect.