This ultrasonic dog repeller uses the latest in ultrasonic technology. It is called the SUPER DOGCHASER because it uses two ways to repel a dog. One is the discomforting, but not harmful, high frequency sound (20,000Hz-25,000Hz), audible to dogs but not to humans. And, the second is a super bright LED flashing strobe that temporarily blinds and confuses the dog. Helps stop the approach of unwanted dogs up to 40 feet. Also has a training setting. Requires one 9 volt battery. Can be used as a flashlight.
When I was walking with my 2 small dogs, a huge white dogs started to bark at us, I used this dog chaser, whoa, the big dog stopped barking, effective!