1. Advanced and powerful ultrasonic technology, which has frequencies between 10KHz and 100KHz. 2. With insect-repellent LED light inside, which can emit light of 560-580 nm wavelength, keeps mosquitoes and other insects away. 3. The reflect board strengthens the light. 4. Plug-in and ultrasonic function on, and the indicated light will be on. 5. With different switches to control the ultrasonic and the light. 6. Can be used as a warm night light. 7. No harm to humans and pets.