Made of Zinc alloy. Sturdy, durable and dependable to provide a lifetime of security and peace of mind.3 Dial Combination can be set and rest to any combination of your choosing for added security. Large dials with easily visible numbers make it easy to line up the numbers correctly, even for the hard of seeing.These combination TSA locks are 100% TSA approved.Not only for securing your trip, but smaller lockers and cabinets, cases and bags, chains, hasps and more.