Perfect for those who hike, backpack, bicycle or just love being outdoors! Athletes and outdoorsmen know how important it is to stay hydrated during physical activity. The Multi-function Hydration Backpack features a specially designed 2 liter water bladder with an on/off valve to prevent leaking. Eliminates the need to lug heavy bottles. The Multi-function Hydration Backpack is equipped with adjustable straps and also serves as a durable backpack, complete with storage pockets to hold necessities such as snacks, keys, camera, phones and more. The entire unit weighs less than 1 lb.