This is a cable passage system that goes from the wall to the back of a video wall to ensure that the dangling cables cannot be seen from the front. The system includes a shelf to be fixed to the wall, for supporting small electronic equipment, and the modules. where to pass the cables inside, the system is expandable as to assemble it 2 threaded bars of diameter 6 must be integrated, the length depends on your needs, I made it from 1 meter but no one is stopping you from making it longer or vice versa.