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. Best choice for short journey and easy your daily life. PORTABILITY - The back sleeve design allows the backpack to slide over the luggage handle for easy mobility during traveling. Padded top handle is implemented on the backpack to allow comfortable carrying. ANTI-THEFT DESIGN - An invisible zip pocket on the back to place your iPhone, keys and wallet conveniently. Anti-explosion double zipper of main compartment is anti-slashing and water resistant, this would increase the security of your stuff inside. WATER-RESISTANT - This backpack is made of water-resistant microfiber leather and durable ballistic nylon materials. The massage and breathable design for back side prevents you from hot and sweating, so comfortable for your daily life. ( Best choice for you in travel,business,office ) 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. As father's day gifts