Harness the benefits of Hydro-Inertia training with the BOSU® Hydro Ball by utilizing water to create an unstable resistance. Hydro-Inertia causes your muscles to react faster, enhances your balance and stabilization, and strengthen your joints. Unlike traditional weights, such as dumbbells and kettlebells, you only need one Hydro Ball due to its adjustable weight capabilities. Product Features Hydro-Inertia Workouts Downloadable Wallchart Adjustable weight Improved balance, stabilization & core strength Anaerobic & Aerobic endurance Full range & full body exercise Additional Details Hyrdo Ball 12 is 12lbs when fully loaded with water