Gravity At Work :See before your eyes as the Newton Balls transfer fall and transfer weight across the gadget. Drop one ball or two balls. You can see the energy transfer in such an astounding way! Office Desk Decor :Show some character and express your love for science and physics with this decorating your office space. Can be meditative and fun to watch also! Educational & Classy :Experience the visual display of momentum. Use this in class and share with your friends and family the exciting world of physics and science! Perpetual Motion: The pendulum balls show the conservation of momentum and energy, creating perpetual motion,these swinging kinetic balls are perfect addition to your office desk decoration accessories or teaching tool at schools. Good Gift Idea: Suit for both kids and adults, excellent for learning science, killing boring time and releasing stress, which makes it a good present for birthday, holiday. Meanwhile, It???s not only a toy, but also a good desk decor. You can put it on your desk or shelf, and swing it anytime when you passing by, it will be a wonderful scenery in your home or office!