Check the listing for details. Ear Listen Through Wall Device Bug Eavesdropping Wall Microphone Voice Spy Set. Condition: New. Listed at 10.99 USD. Features: Simple and powerful to adjust through a handheld listening device, this audio gadget allows you to hear conversations with other obstacles through the switch. Therefore, its working principle is very simple, plug in the earphones, and then put the audio collector on top and listen to what is said When someone is talking in the room, their voice is just a waveband. According to the volume of the call, the waveband can move short and long distances. These wavebands are picked up and amplified by this device. The sensors on the original audio gadgets sense the vibrations inside, the floor and the floor, and amplify them so that you can hear the words. The dial on the back of this cool audio gadget adjusts the volume and increases sensor amplification. It really makes "" more interesting and efficient. So why not find the truth, whether you are placing a room, a hotel room, an apartment or the next room, what kind of thing the device will make you into. specification: Material: Plastic Product size: 35mm * 35mm60mm Weight: 45g The package includes: 1 * Sound amplifier 1 earphone 1 *Charging cable