BOSU Hydro Ball 25The SURGE Hydro Ball 25 Pro is a professional grade piece of workout equipment which has been built to take the most absurd abuse and the most extreme workouts. The HB25 Pro uses water as its source of weight which provides instability, targeting and activating more muscles than traditional weights. This not only makes the HB25 Pro a great training tool, it also allows for the weight to be adjusted up to 25 lbs based on client or workout needs. Use