DOGTEK"s Sonic Birdhouse has the appearance of an ordinary birdhouse but in fact,it"s a state of the art bark control device the uses high-pitched ultrasonic sound technology to deterunwanted barking from either your or your or your neighbor"s dogs! How does it work? When the DOGTEK® Sonic Birdhouse is within range of a barking dog, the internal microphones sense the barking and the unit is triggered automatically. The DOGTEK® Sonic Birdhouse emits an ultrasonic sound which is heard by dogs but is not detected by humans. The dog will stop barking when The DOGTEK® Sonic Birdhouse emits it high-pitched, safe and effective tone. The dog will begin to associate their bark with this unpleasant noise. When the dog stops barking the ultrasonic tone will also stop. The DOGTEK® Sonic Birdhouse has 3 sensitivity levels and a test mode to choose from. It is effective up to 50 feet. Possible Uses for the DOGTEK® Sonic Birdhouse: • Stop your barking dog. • Stop your neighbor"s barking dog. • Train puppies not to bark. • Deter barking dogs on camping trips and when you are on the go. Requires one 9V battery (not included).