... base on electro-magnetic coils.It makes any hard surface play euphonious musical notes,such as wood,glass ... ,floor,metal surface,etc.You can hear various materials aroud you ... Taking ,please put it on hard surface upward ,and let the pedestal touch the surface tightly. 2. Functional parameterInput ... bottom,so you must let it touch the surface tightly.Do not put it on stoves,burners ...