Good to know- Get a full-body workout at home - these adjustable kettlebells let you build muscle and burn calories without going to the gym- Choose the right weight for you by simply filling each kettlebell with up to 8 litres of water- Hydro Inertia Training uses the water as a live weight to strengthen your core- You can make a barbell by joining the two Bells together - they're perfect for toning your whole body- The deflatable design means they won't take up much space when stored away