Setting a vibration speaker down on a solid surface positions, The solid surface will vibrate with the speaker, displacing air molecules around it. Just as with any other sound, your ear detects the movements of the colliding air molecules.
Innovative vibration speaker
Work with any audio device with a 3.5mm jack
Built-in 600mah Lithium battery
Mini Size, Pocket portable
Connection in series,you can creat unbelievable powerful sound