I'm rating this with 5 stars because I love this luggage lock.  I'm one of those people who simply can not trust my unlocked luggage to go through all that the airlines baggage handlers do with it while in their domain.  What do I love about this lock?  Well, no more tumblers to fuss with trying to get them to line up correctly.  No more keys to search for or misplace.  Pacsafe locks are TSA approved and locking/unlocking could not be simpler.  The credit card sized "key" card is easy to carry with you, takes up almost no space, and the best part - it works every time.  Just line up the little holes, insert into lock and bingo! opens/locks no fuss no muss!  I highly recommend these locks - you will love them too!

August 2013 update: still totally in love with these locks.  My only issue, and it's not with the locks, is: TSA keeps cutting them off! Even though Pacsafe is TSA approved so they can check luggage by using their special lock opener, I have retrieved my luggage to find my wonderful Pacsafe lock is missing - 3 times now.  So beware of the TSA!  My solution, which may not be for everyone - I travel with an extra Pacsafe lock!  And with my fingers crossed that the next time I travel, my Pacsafe will still be securely on my luggage!  happy travels!