This is Top Mystery by Andrews Mfg: a 1977 spinning top that keeps going on its base. There is a battery, coil, steel core, and transistor inside that keep the magnetized spinner going. You simply have to install a fresh battery to get started.
once you attach the battery, a magnetic field is created that keeps the spinner going. The transistor acts as a switch, so when the spinner stops, the motor is shut off to prevent battery train.