Build Your Own Bat Detector: What is it? It’s a simple but oh-so-cool kit that lets you build a bat detector, which means you’ll be able to listen to bats & other ultrasonic animals! About the product It comes in kit form, but building it is super easy. Much of it comes pre-assembled & the other parts fit together with simple connections that don’t need soldering or anything like that. Once it’s built, you’ll be able to set the frequency & volume & listen for bat signals through the speaker! How is it powered? It’s powered by a single 9V battery, which isn’t included. Why you should buy it Buy it because it lets you tap into a whole world that’s out there, but that you just can’t hear! Order your Haynes Build Your Own Bat Detector Kit now!