Timbuk2 Especial Tres Backpack (Medium) Backbender flexible cooling panel for superior ventilation and comfort. Air jet textured for high abrasion resistance and exceptional strength to weight ratio. Comfort backpack straps with hydration or headphone routing, a reflective hit and detachable sternum strap. Internal welded laptop pocket for laptops up to 15" inches. Guaranteed waterproofing. Rolltop and swing around side access to the main body of the bag.