The Patagonia Mass Sling combines the support of a backpack with the hands-free convenience of a messenger bag. The main compartment is sized to carry most 13 in. laptops or a tablet. The load of the pack sits right behind your shoulders and preserves arm and torso mobility; spin the single strap around front to easily reach all your gear Main compartment opens with a side zipper; 3 pockets inside, including a padded one for a smartphone, keep small items organized Padded sleeve fits most 13 in. computers or a tablet A molded back panel sheds moisture and allows a cooling airflow and the shoulder straps are padded with breathable spacer mesh to keep you cool Exterior features include a reflective panel and lash point for attaching a light (light sold separately) Patagonia Mass Sling is made of 600-denier recycled polyester with a slick 200-denier polyester lining; both have a polyurethane coating. perfect condition like new.