Pack this lightweight bag in the bottom of your suitcase just in case you come back with a little more then you went with! It takes up very little room and you'll be glad you did. Especially if you're a shopper. It's fun to find treasures when we travel but getting them home can be a pain. This strong ripstop nylon bag can expand three sizes to go from 15" to 21" carry on size. But it is strong enough to check as a suitcase after you've filled it up with treasures. Can also be used as a beach tote or laundry bag. For convenience, it comes with a back strap to slide over your suitcase handle. Don't go on a big trip without it!