1. No battery required. 2. Self-contained mechanism dynamical balanced gyro ball. 3. Increase your wrist strength while having fun. Wrist and finger grasp strength. Forearms muscles strong. The vibration of your arm makes blood circulation well. 4. The speed will reach 8,000 R.P.H. if you are skillful. sound will lead you to a new & explode experience. 5.It is suitable for adult and teenager. The material is polycarbonate, one pc in a Color box,60pcs per carton. N.W. 16kgs,G.W. 17kgs, carton size:445x305x355mm,Ctn CBM 0.0482m3,1X20FT /35460pcs.