Bell + Howell Solar Animal Repeller - Protect Your Yard From Unwanted Pests Built-in infrared motion detector covers up to 30 feet at a 100 angle. Uses an LED strobe light and broadcasts sudden ultrasonic and sonic signals to drive away animals with 7 sweeping frequencies so they don't get used to the sound. Solar-powered repeller also works with 4 "AA" batteries (not included) for shaded areas. Can be mounted to tree or fence, or use included garden stake. Set to "OFF" mode when family pets play outside. 5.25" x 4" x 3.75".