Features: Great educational physics science toy to help kids understand the principles of conservation of momentum and energy in a easy way. Powered by 2pcs AA batteries, move lightly, it will keep going on rocking around until you stop it or power off. (Batteries are not included) Antique semi-globe frame and stylish design, perfect for home and office decoration. Perfect gift for your children, friends or coworkers. Made of high quality metal and plastic material, tough and durable to use. Specification: Material: Metal + Plastic Color: As picture Battery: 2pcs AA batteries(Not included) Size: 18.5 x 10 x 9 cm / 7.3 x 3.9 x 3.5inch(Approx.) Package list: 1 x Revolving Gadget 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.