Carry on Travel Backpack It is a high-quality backpack, we studied a lot of customer needs, put a lot of effort into design and details, and finally finished. With durable construction, smooth zippers, multiple pockets and anti-pirated design, the Travel Backpack offers great value, making it a huge investment for frequent travelers. According to the packaging method and content, the actual available capacity is between 38-40L. Product detail Zipper with logo Double zipper pulls are designed for the main pocket of this bag. Zip lockable-protects things from being stolen Chest Brace with whistle When the backpack load is heavy, the chest brace,can reduce the weight of the back,meanwhile with a whistle, which helps with survival in the wild. Shrinkable Webbing On the journey, you can quickly hide jackets or other items USB Charging Port Equipped with a USB port,offer you a more convenient way to charge your cellphone while walking. Please note that the backpack does not carry power. Multiple Carrying Methods