docooler Electronic Ultrasonic Pest Repeller Mosquito Ants Spiders Roaches Repelling 100V-240V Non-toxic Works by continuously transmitting a powerful range of ultrasonic sound waves that drives away pests. Sound wave frequencies are non-toxic and harmless to humans and pets, an alternative to toxic chemicals and dangerous traps. Protects an area up to 60 square meters if there is an open space. Turn on the switch on the right side and then plug in the outlet. Does not interfere with the operation of radio, television or other electronic equipment.