… records that must be kept under lock and key …

The records are held in safe custody in shelf systems built into steel storage containers. Each container is separately furnished with an electronic lock. This means that access is exclusively possible for authorised persons. This form of records storage is suitable for documents with a medium to high security rating. And is generally more likely to be used for living than for data storage media. (E. g. account documents of banks, insurance contracts, bookkeeping documents)