The kettlebell has long been a favorite for those seeking a special edge in strength and endurance. Kettlebell training develops strength, power, endurance and balance. Working out with kettlebells will sculpt and tone the entire body because lifting and controlling a kettlebell forces the entire body, and specifically the core, to contract as a group, building both strength and stability at the same time. Kettlebell workouts engage multiple muscle groups at once. They are a great option for getting a whole body workout in a short time. Made of solid cast iron, these kettlebells are both versatile and durable. Warning: This product contains one or more phthalate chemicals known to the state of California to cause birth defects and other reproductive harm. Consumer may return the product for a full refund, including shipping cost for both receipt and return of the product within 15 days of his or her receipt.