Features: brand new and high quality Classic Newton's Cradle: This is a classic Newton's cradle balance ball for desk decor, drop one ball on one side, the energy transfer interior and you'll see the other side's first ball will fly accordingly, the movement will last about few seconds and stop without further push. LED Light Function: Equipped with LED bottom base, powered supply by 4 x AA batteries(packing excluded), you can turn on the light button and active the LED light, show you a fancy handicraft suitable for table decoration. Educational Toy: The toy great for express the gravity and the conservation of energy, a good educational aid for class or physic enthusiasts, make you to experience the visual display of momentum and energy transfer. Stress Relief Toy: Assist to release stress when you feel boring or tired, just drop the ball and see it moves under the gravity, smooth and ease your for restless emotion, achieve to relieve tension, eliminate anxiety, enhance brainstorming, and increase the fun of learning or work, which is helpful for kids,toddlers , adults, a brain stimulation toy & good educational toy sets, and improve concentration. High-quality Materials: The middle balls made of high-quality frosted glass with exquisite technology, hanging by strong bearing toughness string, non-toxic and eco-friendly plastic material bottom base,no burrs at all to which are safe for playing, the solid ball improve the gravity of the balls make sure the steady energy transformation. Best Choice for Kids or Adults: Suitable for kids and adults as birthday gifts, Christmas gifts, and best choice stress relief toys, especially for desk decoration office table decorations. Specifications: Product Dimension: approx. Large size 15 x 15 x 11.5cm/5.91 x 5.91 x 4.53 inch, medium size 12 x 12 x 9cm/4.72 x 4.72 x 3.54 inch Material: ABS Plastic, Metal, Glass Net Weight: Large Size 312g/0.68 lbs, Medium Size 183g/0.40 lbs Color: As pictures shown Model Option: Black Base(Large Size)/Black Base(Medium Size)/Red Base(Large Size)/Red Base(Medium Size) Power Supply: 4 x AA Battery (packing excluded) Note: Please allow 1-2cm errors due to manual measurement. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1 x Newton's Cradle Fidget Toy