Chinese Health Ball Daily Exercise Stress Relief Handball Therapy Massager Balls Specifications: Material: Iron, Resin, CopperSize: Diameter 4.45cm Features: -In addition to relieving stress, Chinese Health Balls or Baoding Balls are known to improve joints, blood circulation, sleep patterns and memory. -Two or more Baoding balls are rotated repetitively in the hand to improve manual dexterity and strength, and they are also said to assist in injury recovery. -Each ball measures a bit over 1.5 inches in diameter. Beautiful decorated box included. Soothing chimes inside to further reduce stress. How to use: When exercising, put two balls in your hand, relying on five fingers flexion and extension, so that the two balls circled with each other, the rotation direction of Shun, inverse of the points, so that all the joints in the hand are in motion . With the hand flexion and extension, exhibition income, front wall muscles can have a rhythm of contraction and relaxation. Hands can be alternating exercise, but also three or four balls at the same time rotating, playing a few tricks Material: IronSize: A: Diameter 44.5mm