This TSA Lock features a 3/4" steel shackle and an all metal design. It has an easy-to-use 3-pin tumbler and works with all Bulldog locking zippers. This TSA Lock with Steel Shackle is TSA-accepted and Travel Sentry Approved. (Using a Travel Sentry Approved lock allows your luggage to be unlocked and inspected by security authorities without cutting off or breaking open causing damage).