Easy to Use – Just plug the electronic pest control ultrasonic repellent in power sockets; It will start to repel the pests when the blue light on More Safe for Child & Pets – Ultrasonic sound is inaudible to humans and household pets,environmental friendly alternative to dangerous poisons and Sprayers, chemicals and traps, no bad smell and Corpses Simple In Use & With Blue Night Light – To install our Ultrasonic Pest Repellent you just need to plug it into an electric Outlet. When the blue LED Night Light comes on, that means that the Device is working & this ultrasonic Rodent & Insect Repellent has started to drive Pests out from your Walls, Floors, Cellars & Attics Large Coverage & Silent Operation– This Ultrasonic Pest Control operates silently so you can calmly set it up in a child’s Room, a Bedroom or a Guest Room. Pest Repeller can effectively cover & control Area of up to 800~1200 Ft2 per Device. Installing 1 Device per Room is recommended. Note that Ultrasonic Waves can’t go through solid Material & Walls, so don’t place Furniture or any other Objects in front of it & keep Doors & Windows closed, to allow ultrasonic Waves to expand & work Noiseless – The ultrasonic waves that this repeller sends are far beyond the hearing range of human-beings. Enjoy a peaceful & pest-free tight sleep without any concerns for noise, keep your family have a good sleep form the noise