Safe and Reliable: This electronic pest repeller is safe for human and our lovely pets like dogs and cats. Odorless, quiet and radiation free, safe for pregnant woman and baby. Easy to use: just plug our electronic mouse repellent into the outlet and let it do the rest. And must be vertical to the ground and plugged into the outlet. Please install our item 80-120cm from the ground. Typical results may take 3-4 weeks depending on the severity of the pest infestation. Ultrasonic Insect Repellents: This mouse repellent emits different frequencies of ultrasonic waves to irritate the nervous system of insects. insects and rats, making them uncomfortable and gradually running away. Designed to naturally repel pests so you don’t have to worry about dead pests and rodents. Effective Coverage: Ultrasonic insect repellents are effective in an indoor area up to 80-120 m². We recommend installing one unit per room for best results. But for severe pest areas, we suggest installing 2 or more