This revolutionary device works by using special sound frequencies to humanely train dogs to stop barking. The dog silencer pro™ is trusted by the us military, dog trainers and customers worldwide and works up to 3x farther than the competition. Simple operation: when the dog silencer pro detects barking it immediately sends a high-pitched sound heard only by the dog. Using this proven method, dogs are safely and humanely discouraged from barking. Relax while the dog silencer pro quietly trains your dog, your neighbor's dog or even multiple dogs. No shock technology: our humane training technique uses an age-old principle that teaches dogs to associate their barking with the irritating frequencies. Unlike shock collars that are painful and can be used only on one dog, the dog silencer pro can be used virtually anywhere without you having to ask permission from your neighbors. The dog silencer pro trains dogs to stop nuisance barking (boredom and attention-getting barking) but is designed to have no effect on instinctual or protective barking. Exclusive features: the dog silencer pro is the world's first indoor and outdoor bark control device as well as the first anti-bark unit to operate electrically or with a single 9-volt battery so you have extra portability. Our exclusive high pressure transducer carries sound further than any other anti-bark unit on the market so even the most strong-willed dog can't feign deafness. Remote control: your dog silencer pro package includes a tiny keychain remote control - the only bark control device in the industry to include such a luxury. If for some reason rover is outside the dog silencer pro's 75 foot sound sensor range, you can manually trigger the device with the simple press of a button. The remote control can be used from inside your home, car, or even in your pocket.