BackTpack 3 Ergonomic Backpack, School Bag, Healthy Back Bag, Medium/Large, Leaf Green/Seafoam Carry books, papers and your laptop with better posture and less back strain. Easy access to pockets for phone, eyeglasses; pens, water bottles and books even when you sit State of the art crinkle nylon fabric is lightweight, durable, water resistant, and washable. Adjustable shoulder &amp; hip straps. Chest strap adjusts in height and width. Headphone port. MEDIUM/LARGE 4&#039;8&quot; to 5&#039;11&quot;, 14&quot;H x 13&quot;W side bags; SMALL 4&#039;1&quot; to 5&#039;7&quot;; 13&quot;H x 13&quot;W sidebags.