Does the Leitertec system also work for caravans?

On caravans with hammered sheet metal or other very rough surfaces, the suction cups cannot build up their vacuum. But rubber has the property of having a higher coefficient of friction at higher pressure. This means that the weight of the user makes the ladder much more stable than without the Leitertec system. In addition to the increased contact surface, this results in very similar usage results to smooth surfaces.