1. INTEND USE - Perfectly fit for the Spirit Airline personal carry-on bag size with no charge! The bag has a large capacity and is perfect for travelling, camping, hiking and other needs in daily life. It's also a great gift for others2.UPGRADED SHOULDER STRAP - Upgraded shoulder strap, free your hands, more convenient when you take it to anywhere you want3.FOLDABLE - Can be folded to a small size, easy to carry and save space. The special design enables it can be placed on the luggage.4.CONVENIENT - There is a small bag outside the bag and you can put your wallet/passport/cards and any small items you want to get them more conveniently.5.LARGE CAPACITY - The size of the bag is 18" X 14" X 6",it can bear around 25lb. After being folded, the size is 8" X 7" X 1.5".