The colourful rings of this imposing, desk-top mobile spin and twirl gracefully around a central sphere. The motion is continuous and, at first glance, impossible to fathom. The secret lies in the base; a battery-powered motor spins a powerful magnet, which in turn exerts a force on the weight suspended from the rings. Even when you know exactly how it works, the perpetual, rhythmic movement and gravity-defying structure still fascinate. Packed with retro geek-appeal, this is an excellent curiosity gift line for adults.