High Sierra's Hydra Hike Line is made from durable nylon rip stop material with a 600D coated poly to help protect against the elements. This is the perfect hiking hydration bag for any occasion. Large main compartment with hydration reservoir Organizer compartment with divider pockets and key clip Reflective details on the front and back of the bag for safety Adjustable sternum strap and hip belt webbing Air mesh back panel and shoulder straps