Feature: 1. Uniform Weight: Every ball has been precisely measured for uniform and equal weight, and the high quality ABS base provide more stability, which is simple and elegant. 2. Longer Swing Time: Balance pendulum ball could last for 15‑20 seconds due to the resistance of the friction, you can discover more fun and stress relieving ways to play it. 3. Fun Craft: You can push one ball on one end strikes adjacent sending the one on the opposite end while the ones in the middle stay perfectly still, or two, or more, which can bring you much fun. 4. Stress Relieving: Balance ball craft is a fascinating decoration for your office desks, which is not only could add beauty to the room, but also relieve stress when you playing. 5. Educational: Desk pendulum ball is also a perfectly educational gadget for schools, which can lead kids to understand the meaning of energy conservation. 6. Perfect Gift: The classic design makes this balance ball as a great gift for family, friends and colleagues, so they can relieve stress when needed, while inspiring children to have fun. Specification: Item Type: Pendulum Ball Decoration Material: ABS plastic, glass ball Size: Approx. 12 x 12 x 8.8cm / 4.72 x 4.72 x 3.46in Color: Black Battery Type: 4 x AA battery 1.5V(Not Included). Package List: 1 x Pendulum Ball Decoration