The Deuter Race X Backpack is a versatile hydration packmade for aerobic outdoor activities in varied conditions. Durable constructionand weather protection features allow for year round abuse, whether you're powering up or bombing down a mountain trail on your bike, or speeding through snow on Nordic skis. Mesh covered foam stripes on the back of the pack are designed to minimally contact the body for better air flow and mesh shoulder straps and hip belt wings also ventilate. Moldable internal stays allow customized contouring to differing body shapes while the sternum strap and hip belt both adjustablehelp evenly distribute weight and secure the pack in place. Pads on the shoulder straps protect from chafing. The pack comes with a dedicated zip hydration chamber pocket and 3L reservoir in addition to two mesh side pockets for storing additional bottles or supplies. A front pocket provides space for stashing smaller essentials and a top pocket protects valuables like your cell phone and wallet. You can pack your bike helmet in the integrated helmet holder while you're huffing up a hill, and just as easily stow the helmet holder back in the pack once you reach the top and put your helmet back on. If you need more room for storage, the main compartment expands from 730 900 cubic inches. For weather protection, an integrated, detachable rain coverslides over the pack. Its bright lime color is easy to spot in low lightconditions. With the rain cover off, the pack features reflective features on both the front and back of the pack as well.