The Ultrasonic Pest Repeller works by continuously transmitting a powerful range of ultrasonic sound waves that drives away pests. Non-toxic and harmless to humans and pets, an alternative to toxic chemicals and dangerous traps. Protects an area up to 80-120 square meters if there is an open space. Just plug in the socket, easy and convenient for use. LED light indicates that it is currently working. Safe, environmentally-friendly, effective protection to help eliminate common household pests.