***** **********Best Quality Guranteed. *****INTELLIGENT INCREASE DESIGN - This backpack has smooth zippers on the back side. Once pull on the intelligent zipper, the invisible compartment will show up and equipped with extra 50% of space.. *****PORTABILITY - The back sleeve design allows the backpack to slide over the luggage handle for easy mobility during traveling. *****ANTI-THEFT DESIGN - An invisible zip pocket on the back to place your iPhone, keys and wallet conveniently. *****WATER-RESISANT - This backpack is made of water-resistant microfiber leather and durable ballistic nylon materials. *****PROTECTIVE FUNCTION - Roomy backpack ( 11.8 L * 5.9 W * 17.3 H) with laptop compartment (lined with soft flannel) protects 15.6 Laptop and iPad.