Some Travel Sentry suitcase padlocks like the one below come with inspection indicators which change when the padlocks have been opened by a security official with a master key.
The travel padlock below has a green indicator which turns red when it has been opened by a security officer. Other TS padlocks have a small button which pops out when it has been opened by security officers.
The indicator stays red so that the person with the padlocked luggage is aware that it has been opened by a custom's officer. It is also not possible for the official to reset the indicator to green because the padlock must be opened to using the combination which the officer does not have.
Restoring the Inspection Indicator to green
It is very quick and easy to reset the padlock inspection indicator back to green, although the method might be slightly different for various models produced by different manufacturers.
For the above combination padlock the lock should be opened in the usual way by turning the dials to the preset combination.
As soon as the lock shackle is pulled up and a click can be heard the red indicator is reset back to green.