It's one of the most used listening devices. It comes in different varieties and shapes. The sound clarity is noteworthy within permissible limits. The devices works in a simple way, you just need to point it at the direction where your suspect is and listen. A few of the devices will let you listen clearly from a distance of few yards to hundreds of meters. There are few devices which allow you to listen sharply from as far as 600 meters! I would say this is an ideal spy surveillance equipment.

So this was a small list of spy gear listening devices. There are many other products available out there depending upon your purpose. If you're a professional, then you may get professional spy listening devices, otherwise, you may indulge in saving a lot by getting a decent and more generic listening device or get a spy gear for kids. So the next time if someone gifts you a watch, make sure that it's not one of those spy listening devices. Adios!