Use it to waste time， relieve stress， tune out boring coworkers， or schooling youngsters in physics.Popular as an executive desktop gameStylish and innovative design， very funny and interesting， can also be a great decoration.It is a clever device that not only demonstrates a pendulum， but also shows the Laws of Conservation of Momentum and Energy.Many playing methods. Can try swinging one， two or three balls at onceNot easily fade， durable and solid to use.A great gift for friends or coworkers.Material: Plastic + MetalSize: 17 x 14cm (L x H)Package:1 x Balance Balls Desk Toy