The Qigong balls is very famous in China as one of the three treasures of Baoding, China. They can make both chiming and non-chiming, the chiming one can have a musical chiming sound and increase one's coordination when you are placing them in hand. When the balls are rotated in hand, this will make your fingers have a way as hand massage which would be a great stress reliever for people and as they move against each other. The balls are also well known as, healthy ball, therapy ball, exercise ball, chiming ball, Taichi ball, Baoding ball etc.
Pls contact me freely if there's any I can service