BOPAI Expandable 15.6 inch College/Business Laptop Backpack with USB Charging Point (Black) PREMIUM MATERIAL: Made of hightest wear-resistant,water-resistant microfiber leather and durable ballistic Nylon material. LARGE CAPACITY : Two large capacity compartments with expandable feature fits 15.6 inch laptop. can be easily converted and used as a laptop briefcase. INVISIBLE ANTI- THEFT DESIGN : One hidden zipper pocket equips on the back to pack your wallet, money,The physiological curve back and breathable design gives support and prevents sweating. USB FEATURE : External USB port with built-in charging cable enables convenient charging by connecting your power bank with your electronic devices. TROLLEY STRAP : The insertible pull rod design at the back that allows the bag to slide over the luggage handle for easy mobility during traveling.