Rather than sending a painful electrical shock through their bodies or hurting their ears with damaging frequencies, BarkOff works by emitting a sound which is only audable to dogs and at a comfortable level which is triggered solely by the dog's barking and nothing else.
It is COMPLETELY backed by veteranarians to not damage a dog's hearing or be painful to them in any way which is a welcome change from alternative methods of obedience such as the shock collar.
Immediately after triggering the sound, your dog takes notice of it which causes them to halt their barking immediately. Repetition of the act teaches the dog to equate barking with an interrupting sound so that they stop barking in the situations in which you want them to be quiet. Dogs have different barks which they link to different situations, so this will not stop the dog's barking in all situations across the board.
This means that you can control the situations in which they bark and don't bark which is helpful in conditioning and ensuring they continue to bark in response to "dangerous" situations.
At about half of the size of an average television remote control, you can take BarkOff with you wherever you take your dog and wherever stopping dog barking is an issue as it will not bother anyone else as it's silent to the human ear. It responds to your dog's barking only after you flip it on and is battery powered. It has an effective range of 20 feet, so you can keep it in your pocket on dog walks to teach your dog to stop barking at stranger, have one for the car to keep him quiet on long family trips, etc.