The Guardian Outdoor Bark Deterrent may look like a birdhouse, but it is much more. It is designed to detect barking from up to 50 feet away and correct it with an ultrasonic tone that only animals can hear. The product is a safe choice for all breeds and sizes. Whether you want to stop barking in your neighbor's dog or your own, the unit will quiet them down so you can enjoy the peace. It is waterproof, making it durable for outdoors during all weather conditions. The dog bark deterrent unit hangs on a tree or on a fence post and uses a 9V battery. It has four levels of operation including a test mode, and the LED shows good or low battery life. Keep those loud dogs quiet with this ultrasonic bark deterrent.