Guard your home with a set of 5! Great for the coming season! Effective range: Approximately 32 to 78 tatami mats (1 unit recommended per room) Simply plug it into an outlet. [Electromagnetic waves + 6 types of ultrasonic waves + simulated biological waves] This ultrasonic rodent repellent combines the effects of rodent and mosquito control by adding two types of flea and insect repellent ultrasonic waves to the four types of ultrasonic waves, enhancing it as an ultrasonic pest control device. The improved, most powerful electromagnetic waves + 6 types of ultrasonic waves + simulated biological waves automatically switch, emitting sounds that rodents dislike, driving away rodents and pests, and eliminating them from your home. The rodent repellent is not only effective against rodents, but also against mosquitoes, flies, cockroaches, ants, fleas, bats, geckos, spiders, centipedes, mites, gnats, termites, bees, and lice. 5