I have a camera that runs on four rechargeable AA batteries. When I take it on a trip I like to have at least two sets of spare batteries with me. These used to slosh around loose in my camera bag, and any markings I put on them to distinguish the various sets never lasted long. Now the problem is solved thanks to these handy little boxes. They are lightweight, see-through, strong and easy to open and close. And my camera bag is now tidy. Other battery boxes are available, but these are the cheapest, and as they work perfectly well I can't see why anyone would want to pay more. Oh, and you can clip boxes together to make eight or twelve packs if you want.