The camelbak ultra hydration belt for hands free hydration our lightest hydration belt stores a 17 oz quick stow flask with soft walls that mold to the shape of your body the 3d mesh material stays light and breathable on even the hottest runs and the extra stretch pocket keeps gels keys and cards safely tucked away plus you wonrsquot be stuck carrying a big empty bottle at the end of your runmdashonce the flask is empty just fold it up and tuck it away camelbak ultra hydration