100% polyester. Semi-rigid shell. Large main compartment for documents with large zipped mesh pocket and padded compartment for computer (up to 15") and tablet. The main compartment can be locked with a TSA combination lock to protect the backpack against accidental theft. External C-type and USB connector with internal cable for power bank connection. Internal side pocket for energy bank. Front pocket with zip fastening. Side zipped pocket for storage. Adhesive strip on the back to allow the backpack to be slipped into the trolley handles for easy transport. Padded, breathable back and straps. Invisible pocket on the back, easy to reach when the backpack is in place, ideal for safely storing items such as passports, plane tickets or phones.