the adjustable strap allows it to be slipped to its longest length while strapped on your luggage which would probably be enough to allow the case to be opened enough to grab anything out of the case. To solve this problem, I adjusted it to the exact length needed to be snug around the suitcase I intended to use it on and had it machine sewn in place. Now it is no longer adjustable. While travelling, the TSA left a leaflet inside noting that they did indeed open it and inspect the contents.  It was re-locked and all was well. In reality, a sharp pocket knife could slice it off and whatever valuables inside the case would be gone in a hurry. Like all locks, it may keep people honest and slow down a theif enough to be a deterrent. The body of the lock is made of plastic, has a resettable three digit combination, and a keyhole for a TSA key. Don't let it give you a false sense of security. It does help identify your bag on the baggage carousel at the airport.