Quality lock! - Pelican 1506TSA TSA-Approved Peli-Lock (Number Combination Padlock) for Pelican Cases 1506-TSA

There's a reason you're looking at this lock. It's small, cheap, easy to lock and unlock, easy to change the code (securely, of course), and the TSA won't have to break out the bolt cutters and put you out without a lock for the rest of your trip. The loop is long enough to work on most baggage. The loop is fairly thin, so this won't protect against a determined thief with bolt cutters, but that's not what this lock is meant to guard against. As a defense against opportunistic thieves, this does the trick.