Baoding Balls were first made of solid iron and called "Iron Balls". These solid steel chrome balls are the most similar to the traditional iron balls and are the heaviest kind of balls. Made of solid chrome steel with a smooth mirror finish and chrome plated for protection. A 35 mm set weighs about 0.76 lb, a 40 mm set weighs about 1 lb., a 45 mm set weighs about 1.6 lbs., and a 50 mm set weighs about 2.25 lbs. Rotating these heavy balls will definitely give your hand a workout.
Also known as Chinese exercise balls and Chinese health balls.