The adjusting device is mounted on the Distronic by creating a partial vacuum of 600 mbar with a vacuum pump. A laser beam is then projected on a given "target" (testing device). The adjustment device is tested by the exit of a laser beam through a testing boring. The Distronic-adjusting device consists of a protection housing with centering supports and self-testing device (control device), 3 interchangeable centering rings for different models of vehicles, laser projector, water-level, spiral connection cable with plug, with catch chain and 2 dipsticks.