... to shake any hard surface, like wood, glass, wall, stone and so on, and make hard surface send ... ROHS; CE;CCCMini Sound I-dop MINI Speaker i-dop mini speaker Specifications: 1.high quality 2.best price 3 ... 10W(5-6Ω impedance) Sensitivity:80DBA kind of special speaker, but there is no sound device inside. It ... to shake any hard surface, like wood, glass, wall, stone and so on, and make hard surface send ...