Cast Iron Kettlebell Kettlebells are an ancient exercise tool that have been adapted for modern day living. Whether you want to lose weight, tone up, improve your fitness or get stronger. Kettlebell training can help you achieve your overall fitness goals. Energetics Kettlebells are made from high-grade one piece cast iron. The extra-wide handle design improves functionality while provides a secure comfortable grip. - 10lbs Kettlebell = 4.54kg