1. Easy to use -- just plug the electronic insect repellent into the power outlet; When the blue light shines, it begins to repel pestsSafer for children and pets - Ultrasound is inaudible to humans and household pets, an environmentally friendly alternative to dangerous poisons and sprays, chemicals and traps, free of odors and dead bodies2. Use Simple and blue night lights - to install our ultrasonic insect repellent, you just need to plug it into an electrical outlet. When the blue LED night light is on, it means that the device is working and that this ultrasonic rat repellent and insect repellent has begun to drive pests away from your walls, floors, cellars and attics3. Large Coverage and Silent operation - This ultrasonic pest control operation is silent so you can calmly set up in the children's room, bedroom or guest room. Insect repellents can effectively cover and control areas up to 800 to 1,200 square feet per device. It is recommended that one device be installed in each room. Note that ultrasonic waves cannot pass through solid materials and walls, so do not place furniture or any other objects in front of it, and keep doors and Windows closed to allow ultrasonic waves to expand and work4. No Noise - This repellent emits ultrasonic waves well beyond the range of human hearing. Enjoy a quiet, bug-free sleep without worrying about noise, and let your family get a good night's sleep in the noise