Baoding

Baoding ball were (according to popular belief) created in Baoding, China, during the Ming dynasty. In that town, they call them Iron Balls, because they were originally made out of iron. Now, they come in all types of materials, but usually are light, hollow, chrome plated steel, with an optional chime inside. Baoding balls come in many sizes, usually within 30 (child sized) to 60 (for tall men) millimeters. Area code 312