Features: It is a very funny decompression toy that a ball can be used to hit other balls and swing. Not only demonstrates a pendulum, but also shows the Laws about conservation of Momentum and Energy. Made of steel material, bright, preservative and not easy to rusty. As a creative decompression desk toy to amuse people. Perfect for decorating in the office, home and other indoor places. Can be a funny gift to your friends, family and children. Specification: Condiiton: 100% Brand New Color: Sliver Material: ABS + Steel Ball Diameter: 1cm / 0.39"(appr.) Ball quantity: 5 Small Balls Packing: Carton Size: (L) x (W) x(H) 8.5 x 7 x 9cm / 3.35" x 2.76" x 3.54" (appr.) Package Included: 1 x Balance Balls Toy Notice: Please allow 1-3cm error due to manual measurement and make sure you do not mind before ordering. Please understand that colors may exist chromatic aberration as the different placement of pictures.