The TSA locks (https://www.eisele-koffer.com/Koffer-1279/waffenkoffer-gun-case-zubehor) are special closures which can be opened on the authority side with a general key.
The basis of this development was the tougher security measures in international air traffic with the aim of avoiding damage to the baggage when necessary searches by security or customs authorities were made because they would otherwise be broken up without consulting the owner. With the help of the TSA lock, the baggage can be opened without damage and closed again after a search. However, it can not be ruled out that illegal master keys will be copied and misused. So a TSA lock offers no increased security against theft.
Therefore, we recommend to only mount TSA locks in addition and to use them only during the flight (for this, please do NOT lock the factory-installed cylinder locks).