This led backpack requires connecting to a power bank for use, but please note that the power bank is not included in the product. Therefore, it is necessary for you to prepare your own power bank separately. Multipurpose: LED backpack size is about 13.5 * 7.5 * 18.8in which have enough storage. Large zipper pocket as a laptop bag, put a tablet computer;the interior has a number of independent small compartments, can effectively store cosmetics, tissues, keys, textbooks, mini ipad, cell phones, umbrellas, some sports equipment, etc. DIY: Modify the pattern at will, let the laptop backpack as you wish. It has a sleek and cool design that's easy to spot in a crowd.