The XMark 20 lb. Black Cast Iron Kettlebell XM-3332-20 generates noticeable strength gains, develops power and endurance and improves flexibility and balance. With a higher intensity workout than standard weight training, kettlebell training with the XMark 20 lb. Black Cast Iron Kettlebell XM-3332-20 is one of the most effective weight training workouts for burning fat, losing weight and building muscle. The displaced center of mass forces all of the muscles to stabilize and participate in each movement whether you are swinging, curling or lifting the kettlebell. Maximize your weight training potential with XMark, the mark of excellence.