Using the Latest ultrasonic technology, the Dog Chaser produces a discomforting (but not harmful) high frequency sound, audible to dogs but not humans. Help stop the approach of unwanted dogs at up to 15 feet. Also useful as an aid in dog training. The Dog Chaser features a belt clip and low battery indicator. Comes with a 9 volt Energizer battery Frequency Range: 20,000Hz - 25,000Hz Sound Pressure: 135dB