Prod:# YYBD Pair of Bao- Ding Balls with Decorative Box in Oriental Motif, Dim: Each (2) Sphere is 1.5 " in Diameter. Wght: 10.2oz (.64 lbs) Box Dim:4 1/4"(l) x 2 1/2"(d) x 2" (h) Wght: 10.2oz (.64 lbs)..................Bao- Ding Balls, (Yin Yang) Iron Balls: .....The Production of Bao- Ding Balls dates back to the Ming Dynasty (1368-1644) . Builds up Physical strength and removes diseases. Upon using, the balls can stimulate the acupuncture points on the hand, unblocking vital energy channels and blood flow. Can prevent hypertension and other various chronic diseases. ..................... These would make an excellent gift for anyone needing to exercise their hands and the box adds a nice touch also. Each set includes directions and information on the Bao-Ding Balls.