I got the two pack of the sure lock TSA approved locks. I do not travel very often, but have grandkids and we love to go swimming at the rec center, and we go on a lot of day trips. These locks fit everything I hope they would! They fit my storage box (a generic version of a pelican box) that I keep my gaming controllers in. It also fits the lockers at the gym, and works with my luggage! These locks come in handy for a number of different applications, and since they are TSA approved, it would be very easy to get a replacement key if they get lost and you have forgotten your combination. These locks come with four keys, so I would be surprised if they all got lost.It was really easy to set my own 4 digit combination for the locks. The directions that came are clear and easy to understand. They were well made and are durable. It would be more difficult than I expected to break into these. I am a begginer lock picker, and wasn't able to pick these, but i am not very good yet. The key and combination work differently. The key drops down the piece that holds the shackle, where when you use the combination, it slides over to unlock. This could be useful in tighter situations where what you are trying to lock is in a harder to reach spot.These seem to offer good security, and are lightweight and portable. They feel heavy duty, without adding unnecessary weight. I am very happy with these locks!