OUTERDO Hydration Pack Hydration Backpack Water Rucksack 2L Cycling Bladder Bag for Outdoor Hiking Climbing Pouch Multi-ColorWithout Bladder Bag The Hydration Bladder Not Included Two layers cargo design,one for hydration bladder,and the other for extra carrying purpose Constructed by waterproof high density Nylon material Adjustable shoulder strap and chest belt, suitable for heavy carrying Easy to use on/off valve on the hydration bladder