XINCADA Mens Backpack Book Bag College School Backpack Laptop Backpacks Travel Hiking Bag polyester Scientific and reasonable capacity: The size of this backpack is about: 11.22x5.12x18.5 inches, a special laptop compartment and iPad compartment. Multiple pockets for your stuffs, and can make your things more organized. This backpack is very nice for shcool life, 2-5 days travelling, outdoors and other occassions. Main material: This school bag is made of high quality polyester, durable enough, wear resistant, and water repellent. Unique buckle closure: Buckle closure is different from zipper closure, it is much more easier to close and open the bag, and much more safety than zipper closure. Unique buckle closure: Buckle closure is different from zipper closure, it is much more easier to close and open the bag, and much more safety than zipper closure. Adjustable shoulder straps: You can adjust the length of this backpack's shoulder straps to fit your body, and make your trip more comfortable. And a special chest belt can reduce the pressure of your shoulders and make it more comfortable.