EASY TO USE - Just plug the Electronic Pest Control Ultrasonic Repeller into a power outlet and the blue light will start repelling pests.Safer for Children and Pets - Humans and household pets can't hear ultrasonic sound, environmentally friendly alternative to dangerous poisons, sprays, chemicals and traps, no odors and dead bodies.EASY TO USE, BLUE NIGHT LIGHT - To install our Ultrasonic Pest Repeller, simply plug it into a power outlet. When the blue LED night light turns on, it means the device is working and this ultrasonic rodent repeller starts driving pests away from your walls, floors, cellars and attics.LARGE COVERAGE, QUIET OPERATION - This ultrasonic pest control operates silently, so you can quietly set it up in a kid's room, bedroom or guest room. Pest repellers can effectively cover and control areas up to 800-1200 feet per device. It is recommended to install 1 device per room. Note that ultrasonic waves cannot pass through solid materials and walls, so do not place furniture or anything else in front of it, and keep doors and windows closed to allow the ultrasonic waves to expand and work.No Noise - The ultrasonic waves emitted by the repeller are far beyond the range of human hearing. Enjoy a peaceful, pest-free, tight sleep without worrying about noise, giving your family a good sleep pattern.