Question about Rottner keykeeper

Hello sisnetch
The key safe only needs a four-digit numerical code.

Theoretically, all numbers can be selected at the same time. However, since the order in which the numbers are entered does not matter, it does not make sense to select as many numbers as possible. Each number can only be used once and is set mechanically with a screwdriver or similar.
Six digits, however, is not a problem.