JanSport Revolt Performance Daypack with Ventech/Biovent nylon Ventech lightweight, highly breathable cushioned back panel not only protects the body from objects within the pack, it's engineered with circulation grooves to increase ventilation and create airflow, cooling the user's back New Biovent Shoulder Straps, extremely lightweight molded foam straps conform to your body and evenly distribute pressure. Angled vent holes within each strap provide maximum ventilation, keeping shoulders cooler Two large main compartments for versatile storage Reflective zipper pulls for nighttime visibility Front utility pocket with organizer keeps essentials handy