Perfect size 11.8"L x 5.5"W x 17.3"H with 3 compartmentsMade of 900D polyester printed fabric, inside Lining, waterproof has an inside lining with the reinforced design for long-term use, easy to clean, excellent wear-resistance, waterproof, effectively prevent scratches and tears.Ultra-lightweight 8 oz., offering pain-free and hands-free .Comfortable design with adjustable straps and soft back. It is designed with adjustable shoulder strap/belt and enhanced strap connection that can average two shoulders’ force, reducing the pressure, offering you pain-free, hands-free and stabilityAdded Pencil case and multiple pockets are easy for organizing*The main and middle compartments can store a laptop, pad, books, magazines, folders, etc. There is a unique laptop holder in the main compartment. The 2 multi-functional pockets and 2 pen holders in front compartment are easy to store keys, phone, earbuds, etc. There are two side mesh pockets for water bottles. An additional hanging pencil-case is useful for pencils, crayons, and erasers.