If you have it set to a higher sensitivity and large powerful headphones the battery will run out faster however still work for a very long time. Using bigger headphones and a higher sensitivity will mean you do not miss a thing making this setup brilliant for keeping an ear on things. It 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, the waveband travels short and long distances which are picked up and amplified by this device.
The sensor on this listening bug senses the vibrations hitting the walls, ceilings and floors and amplifies them so that you can listen to what is being said. If the waveband is low, meaning people talking in a lower note, then you can use the sensitivity dial located at the back of the bug to adjust the volume and increase the sensors amplification. It really makes "spying" more fun and productive.1 x USB Charging Cable. The item "Listening Device Spy Bug Sound Amplifier Hearing Wall Gadget Surveillance Secret" is in sale since Wednesday, June 24, 2020. This item is in the category "Consumer Electronics\Surveillance & Smart Home Electronics\Home Surveillance\Home Surveillance Parts & Accessories\Other Surveillance Parts & Accessories".
The seller is "shoppingfunday" and is located in ShenZhen. This item can be shipped to United States.