Electronic Ultrasonic Technology : The electronic pest repellent plug in adopts modern micro-electronic technology can create changeable ultrasound intermittently and alternately. Influences on the auditory and nervous system of pests such as mice, rats, spiders, ants, bugs, cockroaches, mosquitoes, fruit flies, flea, crickets, insects and rodents through unique ultrasonic waves. They will escape spontaneously from the area that the ultrasonic covered. MORE COMFORTABLE FOR CHILD AND PETS. Throw away the harmful poisons, dangerous chemicals, and traps typically used in households and by control technicians. Our product is 100% environmental and effective. Ultrasonic sound is inaudible to humans and household pets; Environmental friendly alternative to harmful and dangerous chemicals, poisons and traps, no bad smell. Easy Installation: Simply plug the device in to household power socket vertically.Installing the devices 30-70 inch from the floor is recommended. The blue LED light illuminate,indicating the device is working. Wide Effective Coverage: The pest repellent ultrasonic repellent is effective in an indoor area up to 1600 sq.ft. Its widely used in bedrooms, warehouses, kitchens, offices, gardens, etc. One unit one room is recommended, because the ultrasound could not go through walls and solid objects.For serious pests problem, we suggest install 2 or more devices in one room. Easy to Use: Ultrasonic Pest Repeller just plug the electronic pest control ultrasonic repellent in power sockets, Please make sure to install it vertically 7-31 in away from the floor. And make sure there are no barriers like curtains or cabinets covering in front of the repellent. Most customers can see the results within 2-3 weeks Then we can say goodbye to Vermin