This unit was designed to transmit ultrasonic waves that are able to be heard by dogs up to 50 feet away. The ultrasonic sound emitted by Dog Bark Eliminator gets the dogs’ attention and helps coach them towards improved behavior. The sound is irritating to dogs, and is inaudible to humans. Dog Bark Eliminator is ideal for training dogs or for mailmen, speed walkers, joggers and everyone. Dog Bark Eliminator can be used as a coaching device. Help control dogs that dig through your trash or flower beds. Coach your dog on what furniture they’re not allowed on. Use the highpitch signal to train a dog and improve its behavior.