The casual daypack built in USB charger outside and built in charging cable inside. Your electronic device can be charged conveniently when you are walking. Please noted that this backpack doesn’t include a power bank, usb charging port only offers an easy access to charge. Water resistant High-quality canvas with complete lining, load-bearing but lightweight. Padded shoulder straps are wide with high permeability material, decreasing pressure of shoulder and neck, and keeping cool when you carry it for a long time. Basic style book bag is perfect for junior senior college school students, also applies to hiking, riding,work, business, etc.