OUTER MATERIAL : Polyester, Inner Material : Nylon ORGANIZER:This backpack hangs nicely and comfortably on your back and shoulders. You can organize your tools with the differently sized pockets. There is plenty of room for your keys, cellphone, wallet, etc. Good quality zippers allows it to slide easily and smoothly. The padded laptop compartment fits your device snugly while the main compartment is best for holding heavy textbooks. COMFORTABLE AND ADJUSTABLE SHOULDER STRAP - According to human engineering design, adjustable and durable shoulder straps for carrying comfortably, can better fit the shoulders and long time to bear.