①. How it works - this Ultrasonic Pest Repeller emits ultrasound at a frequency of 22 - 45khz via an ultrasonic and electromagnetic dual chip which interferes with the brain and auditory nervous system of pests and protects your home from pests, mice, rodents and mosquitoes. ②. Easy to use - the repellent is simple to use. All you have to do is plug the ultrasonic insect repellent into a power outlet and it will start insect repellent when the blue night light comes on. It is recommended to install this insect repellent between 30 - 50 inches from the ground (for flying pests) and 10 - 30 inches off the ground (for crawling pests). ③. Wide effective coverage - mosquito repellents can have a working area of up to 1200 square feet; Since ultrasonic cannot penetrate walls and solid objects, place mouse repellent in every room, 6-12 units is enough to repel pest control indoors (depending on severity of infestation). ④. Children and pets are safer - ultrasonic repeller works with low frequency ultrasound, it's hard for humans to hear, An eco-friendly alternative to dangerous poisons and sprays, chemicals and traps, no foul smell and no carcass, effective against rodents and pests. ⑤. Effective work - insect repellent works 24 hours a day, 7 days a week. Most customers can see results within 3 - 4 weeks. The repeller should be placed in a location where its noise will not be affected by walls and furniture. It is widely used in home, warehouse, office, garden, hotel, etc.