Here is a very special system from CISA :
a double-bitted lock + 11 pin-tumblers !

It consists on adding a second lock-system on an existing lever lock.
First the key is inserted in the round cover of the lock contening a system with 11 pins
(6 on one side of the key, and 5 on the other side).
If it is the good cuts, the key can be turned 90° and it's ok to go on with the 2nd part
of the mechanism (double-bitted lever lock).
This prevent lock from being picked, and prevent also from introduction of tools.