Personal Item Bag 18"x14"x8" For Spirit, Frontier and other el Cheapo Airlines Under the Seat Small Bag for Airlines Smart design: Starts off with a 17.3" x 10.6" x 6.3" bag with soft sides. If you need more space you can stuff it and the bag swells up to the regulation 18"x14"x8" limit but does not exceed it. Smart Looks: Most bags in this category are drab canvas bags. These are nicely designed graphical prints. Moisture resistant. Folds flat when not in use - saves space. External long zipped pocket with cover flap. Most other bags have a small zipped pocket if any at all. Flap covers the zip so others don t see the zip. Just an added safety measure. Just because you are traveling on a budget airline doesn t mean your luggage has to look like a drab prison bag. Travel with a stylish bag and we won t tell :)