Good item. This is a speaker that uses vibrations to operate. No need to place them on stone, it's better to place them on smooth surface furniture so that the suction cups at the bottom have good contact. The only disadvantages are the battery and lack of power. That being said, we can keep it plugged in via USB with a power bank, for example. It's good for setting a little ambient sound. We are having fun placing it everywhere to see how it reacts and how the sound spreads. The icing on the cake, you can make them appear by simply pressing the 2 speakers at the same time 5 times in a row. Recommended, good value for money.
