Specifications: This ?Enigma Roller? is used for the study of how the magnetic force reacts with metals around it. Users can use the handle to place near the metal plate while spinning, users will feel the vibration occurring as a result of the magnetic force. The plate has a diameter of 25 cm, the plate can be spun, inside the plate, there are 16 metal balls embedded in the metal plate. The plate is held on a base with dimensions of 35x35x10 cm. The base is made of MDF wood covered with Formica plastic.