Features 1 In addition to relieving stress Chinese Health Balls also known as Baoding Balls are known to improve joints blood circulation sleep patterns and memory 2 Two or more Baoding balls are rotated repetitively in the hand to improve manual dexterity and strength and hey are also said to assist in injury recovery 3 Each ball measures 42mm in diameter and features the dragon design Beautiful decorated box included Description Type Exercise Stress BallsMaterial IRON RESINBall Pattern YING YANGBall Color BlueCase Color Sent RandomlyBall Size App 42mmCase Size App 10 5 5 5 5 5cmWeight App 190g Package Included 2pcs X Exercise Stress Balls With Case Notes 1 The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness 2 Please allow slight deviation for the measurement data