PetSafe 25 ft. Ultrasonic Bark Control

This tabletop device automatically stops your dog's barking, giving you peace and quiet in your own home. Simply put it on a table or counter in the room where your dog barks the most. Whenever your dog barks, all pets within range will hear a 2-second ultrasonic tone. You can can set it to go off automatically every time your dog barks or manually press a button to make the tone sound. Your dog will learn to associate his barking with the unpleasant high-pitched sound that's inaudible to most humans. Most dogs bark less within a few days. The device covers 25 feet, about the size of 1-2 rooms in a typical house. Add an extra unit for larger rooms or one unit for each room in your home. If your dog barks throughout your home, consider a Bark collar instead.