Get rid of dogs and protects you while jogging, cycling, or walking. Harmless dog repellent uses sound waves to drive dogs, cats, coyotes and wolves away. Produces a high frequency sound (20,000Hz-25,000Hz) that the human ear can not detect, but drives dogs away. Effective up to 20′ feet. Stops vicious dogs from chasing, biting, or barking at you without harming them. Safely use the high-pitch signal to train a dog and correct its behavior.