- Advanced and powerful ultrasonic technology, which has frequencies between 10KHz and 100KHz. - With insect-repellent LED light inside, which can emit the light of 560-580 nm wavelength, keeps mosquitoes and other insects away. - No maintenance required, lasting 24/7. - Plug-in and ultrasonic function on. - With different switches to control the ultrasonic and the light. - Can be used as a warm night light. - No harm to humans and pets.