Petsafe - ultrasonic bark control solution

When the PetSafe® Bark Control is within reach of a barking dog indoors, an internal microphone picks up the sound. The device automatically emits an ultrasonic tone. Most people cannot hear this tone, but dogs can. The dog is startled by the ultrasound and stops barking. Over time, he makes the connection between his barking and this unpleasant sound. When the dog stops barking, the ultrasound also stops. The tone works up to 8 feet away.

Product features
• Automatically discourages excessive barking
• No collar required
• Detects barking from up to 8 meters away
• Indicator light for low battery level
• Free-standing or to be attached to door or window frames, etc.
• Includes two devices for placement in multiple rooms