This is a set of 4 TSA approved luggage locks.I like to use these while travelling.A long time ago I used to use the regular number lock while flying and so many times the TSA boke the zipper and damaged the entire luggage bag,since then I stopped using any locks on my luggage while travelling.But I was always concerned about the content of my luggage especially if its a high valuye item.Iam glad to have these now.TSA does not break these locks or the zippers and I feel safe that my luggage is safe.Overall these are great value and so useful.