Adjustment element

The adjusting element (1) has a housing comprising an elongated sliding structure (3) that is displaceably guided into an outlet opening (4) of housing. A lock slide (8) is transversely arranged with respect to sliding structure. The chain links (6) for side strand are connected with a hole provided at front end of sliding structure and a bolt (7) mounted at rear region of housing respectively. An end stop is provided in sliding structure.