Montbell Trail Water Pack 3LA hydration bladder with a tube that allows you to drink when youre on the go? No need to put your backpack down. Drinking when your body is thirsty helps curb fatigue and makes it possible to hydrate efficiently without drinking too much. The bladder is made with lightweight, strong material that is resistant to absorbing odors. It features a slide lock system that makes for extremely easy filling and cleaning. Specs Material: Body: E. V. A.