Features: The pole and bracket of the permanent ball and the base are made of high quality plastic. Principle: Swing the ball by the force of the hand, then use the energy converted by the battery to continue swinging until the battery is dead. Creative design, rich colors, beautiful appearance. A wonderful addition to decorate your living room, bedroom, office, etc. It is also a nice gift for your kids, friends, families, workmates, classmates and more. Specification: Material: Plastic Color: Shown as picture Battery Type: 4 x AA batteries (NOT included) Weight: 230g (approx.) Package List: 1 * Newton Pendulum Ball 1The pole and bracket of the permanent ball and the base are made of high quality plastic. 2Principle: Swing the ball by the force of the hand, then use the energy converted by the battery to continue swinging until the battery is dead. 3Creative design, rich colors, beautiful appearance. 4A wonderful addition to decorate your living room, bedroom, office, etc. 5It is also a nice gift for your kids, friends, families, workmates, classmates and more.