MaximalPower Repeller Multi Function Ultrasonic Repellent for Mosquitoes, Cockroaches and Rats Make sure item is sold and shipped by Amazon.com! All other marketplace vendors are selling counterfeit products and are not covered by Maximal Power Uses new innovative method of advance calibrated sonic and ultrasonic frequency waves to drive dogs and mosquitoes away Safe for Children and non-rodent pets and environmental friendly, non-toxic and chemical free Effective up to 4 meters maximum, and best use in Home, Office, School and Warehouse With MODE Function to select the repelling mode of low sound level mosquito, high level mosquito, rat or cockroach