Ultrasonic Wild Animal Repeller GH-326 The product uses ultrasonic sound technology to deter without harm a wide range of animals including Dogs,Cats, Foxes, Rabbits, Squirrels, Deer, Rats, Mice, etc. It has 3 settings to selectively repel those animals that are unwanted. The product does not affect people and fish. Function Selector & Frequency Selector Theory:This prodcut uses variable ultrasonic frenquency to repel different animal automatically.1. High frequency 240KHZ to repel cats.2. Medium frequency 23KHZ to repel cats,dogs,foxes,deer.3. Low frequency 17KHZ to repel mice,rats,squirrels,rabbits and elephants.