Startle pests from your yard or garden humanely and effectively with this hi-tech Motion Activated Ultrasonic Deer and Animal Repeller. Unlike most ultrasonic devices our system has been tested and designed to startle animals but doesn't let the animal become used to the sound. Emits a high pitch ultrasonic blast, just above the frequency of human hearing, which disturbs deer and animals but not you. Covers up to 4000 sq. ft. and has an adjustable frequency range of 5,000-25,000 Hz. The frequency adjustment can be manual tuned to deter rodents, bats, skunks, opossums, armadillos, raccoons, deer, and insects. The motion sensor has a range of 35 feet x 70 feet, and activates when pests move into the coverage zone. The Motion Activated Ultrasonic Deer and Animal Repeller is powered by a 50 ft. plug in AC adapter(included) or 4 C-cell batteries(not included).