Do you want to ensure that keys with special functions or access rights can only be used by certain people and that after use they are stored in a safe place and cannot be removed from that depository?

The mechanical key depots 1500D by dormakaba do exactly that.
When an authorised manager key is inserted in the main lock cylinder and turned, one or several function keys can be taken from the key depot.
After using the function key, it is reinserted into the key depot and turned. Until then, the previously inserted manager key cannot be removed.
Once it is removed, the function keys are safely stored in the key depot and cannot be withdrawn.