【Ultrasound Technology】: Ultrasonic Mosquito Repellent uses the advanced physical ultrasound technology, which emits ultrasonic frequencies to disrupt the central nervous system of parasites. Effectively repels mosquitoes, cockroaches and other parasites. 【Wide Coverage】: Ultrasonic Mosquito Repellent can effectively cover a range of 161-215 square feet. Since ultrasonic waves cannot penetrate walls and solid objects, it is recommended that insect repellent be placed in a room. For areas with more mosquitoes and larger areas, multiple insect repellent ultrasonic waves can be placed. 【Safe and environmentally friendly】: Ultrasonic mosquito repellent uses low frequency ultrasonic waves to influence parasites’ brain waves, physically repelling them rather than killing them. Free of chemicals, non-toxic, odorless, safe for both humans and pets. No need to clean up corpses, the ultrasonic insect repellent is environmentally friendly. 【Wide Uses】: Ultrasonic rat repellent are effective in