SAS Hydration System Bladder Water Bag Pouch Backpack for Hunting Hiking Climbing Equipped with a tube with a bite valve to drink, so you don't need to hold it to drink. Two layers cargo design, one for hydration bladder, and the other for extra carrying purpose. Perfect to use when hiking, climbing, riding and other outdoor activies. Adjustable shoulder strap and chest belt, suitable for heavy carrying. Constructed by waterproof 600D high density Nylon material.