Update Electronic Ultrasonic Technology - The Ultrasonic Pest Repellent use the dual ultrasonic and electromagnetic chips work simultaneously to disorientate the hearing and nervous system of pests to quickly and powerfully drive them away. It can drive away most types of flying and crawling pests such as mosquitoes, spiders, bed bugs, cockroaches, mice, fleas, ants, fruit flies, etc. New Multi-layered Frequency Technology - With this new multi-layered frequency technology it could expand its coverage area for a full blast of repelling insects indoors up to the garden. One unit of the ultrasonic pest repellent covers up to 100m, which suit for house, warehouse, office, hotel. Safe For Human/Pets - Destroying the living environment of the pests physically, the ultrasound waves only effects on pests and mice. For child/pregnant women/The aged/pets, pest Repeller is safe and not interfere with domestic appliances. Quiet and non-radioactive operation. Plug And Play - Just plug the electronic pest control ultrasonic repellent in power sockets or the outdoor socket it will start to repel the pests when you notice the light is on. Recommended to plug the ultrasonic pest control repeller at between 32-47 inches away from the floor for flying pests.