Ventilation Whatever your distance, the Hip Pack Pro 3L can be individually adjusted to provide the perfect level of ventilation along the back panel thanks to an Air Flow Contact System with specially grooved channels and EVA Pads behind mesh material, practically moved to the inside to maximize comfort. As with all Evoc packs, the circulation technology optimizes ventilation, preventing excessive cooling of the kidney area throughout high strain activity. Gaps along the sides of the channel also allow air to freely escape. Comfort A Venti-Flap system folds the back piece away for maximum ventilation, enhancing your carrying comfort by opening the adjustment straps over longer ascents, increasing ventilation. As you descend, the pack can sit firmy and completely natural to movement. With 3D Air Mesh strategically placed over the shoulder straps, cushioning is optimized, sitting comfortably on the hips throughout. Organization With minimal space, the Hip Pack provides impressive on-the-go organization, accomodating two bottles to keep you hydrated. A smartphone specific pocket is easy to access and a nutrition pocket will keep you moving from dawn to dawn.