Upgraded Version of Ultrasonic Insect Repellent:Ultrasonic Mosquito Killer Plug, 45mm diameter speaker. 18 frequencies of sound waves in all directions 360 degrees, Intelligent frequency conversion stimulates the sensory system of mosquitoes, Effectively repels insects, ants, mosquitoes, flies, cockroaches, mice, bats and other parasites. Security: Ultrasonic Anti Mosquito Repellent is specially designed for pregnant and infant families, It is non-toxic and harmless. The frequency of 3D surround sound waves emitted by the insect repellent, Ultrasonic frequency 22~65kHz, Only affects rodents and pests, It does not emit electromagnetic waves! It is absolutely safe for pregnant women, babies, family members and pets. High Quality, Energy Saving: Ultrasonic Insect Rodent Repeller is made of high quality ABS flame retardant material, which is high strength, high temperature resistant, anti-aging and durable, safe and reliable to use. Battery-free ultrasonic mosquito repellent. It consumes