Product Overview: This audio gadget works by amplifying the vibrations of audio. When people are talking in a room their voices are simply a waveband, and depending on how loud they are talking, waveband travels short and long distances which are picked up and amplified by this device. This is a highly sensitive audio device which works on wooden walls, doors, windows and steel plates. This is a highly sensitive audio listening device. The sensor on this gadget senses vibrations hitting the walls, ceiling and floor and amplifies them so that you can listen to what’s being said. If the waveband is low,this means people talking in a lower note, use the dial located at the back of this device to adjust volume and increase sensors amplification. Package: Listening Device Earphones USB Cable Power Charger (110-220v) Order your Spy Bug Wall Gadget Today while supplies last!!