Features: 1.Electromagnetic Drive Power: This perpetual motion machine adopts electromagnetic drive power and law of universal gravitation, making the perpetual motion device runs stably with a much lower sound. 2.Stress Relief: This perpetual energy toy allows you to temporarily relax your brain when you feel tired from work and life, quietly observe the trajectory of the metal balls, which will make you forget your troubles immediately. 3.Stable Base: This perpetual motion device is designed with wide and stable wooden base which ensures exquisite texture and high stability. 4.Wide Application: This perpetual marble machine is perfect for outer space science themed classes, living room, wall, home, dining room, bar, office, hotel, and outdoor environment. 5.Perfect Gift: This perpetual motion simulator is perfect gift giving choice on birthday, Christmas and other holiday for your kids, friends and family. specification:Item Type: Perpetual Motion Machine Material: Oak Quantity: 1 Set Product Use: Household Applicable Scope: Most Scenarios Product Size: Approx. 15 x 19cm / 5.9 x 7.5in ( Manual Measurement, Slight Error May Exist ) PackageList:1 x PerpetualMotionMachine 5 x Ball 1 x Power