Item specificsGender: UnisexAge Range: > 6 years oldMaterial: MetalFeatures: MiniItem Type: SetProduct DescriptionNovelty Constantly Rotating Magnetic Gyro Magnet Spinning Top The " top secret " consists of a spinning top with a radially oriented magnetic field and an associated base that houses a conductive coil . when the top spins past the center of the base ， its changing magnetic field induces a current in the coil momentarily which opens the switch to the battery resulting in powering up the electromagnet . the electromagnet then delivers torque enough to the spinning top to allow it to spin speed up and away from the center . since the electromagnet is engaged only when the top crosses near the center of the base ， one 9 volt battery can last for over a week of continual use !Features Color: Silver Material :Electromagnetic+ABS Size:Black chassis diameter of about 8.8cm， gyro diameter 1.9cm， 2.2cm height Box size :9.5*7.5*5.5cm Packing: Original boxPackage Included 1 x Magnet Spinning TopNote:The product does not contain batteries