... to shake any hard surface, like wood, glass, wall, stone and so on, and make hard surface ... send out the music.(You put it in different material, and by the recombination of "music ... insert the other side into the head-set socket of CD players, laptop, music mobile phone, MP3, MP4, MP5, ... hard surface send out the music.(You put it in different material, and by the recombination of "music ...