Stop excessive, noisy dog barking by emitting an ultrasonic sound to silence the dog. More effective than old version deterrents. Contain sensitive microphone isolates and picks up barking up to 50 feet away to stop barking both outdoors and indoors. FOR DOGS OF ANY SIZE - uses high-frequency sound that works to reduce excessive bark of dogs within hearing range; for dogs 6 months and older UP TO 50 FOOT RANGE 100% SAFE. Safe to your dogs of any size, other pets, plants, and of course yourself and your loved ones. This bark-control device has a cute birdhouse shape, adding a nice touch to your yard. You can easily hang it on your fence or on any tree, while the waterproof design and durable plastic guarantee its functioning for many years.