Wide Effective Coverage: The repellent is effective in an indoor area of 1600 square feet. It is widely used in homes, warehouses, offices, gardens, hotels, etc. We recommend that you install one for each room, as ultrasonic waves cannot penetrate walls and solid objects. But for areas with serious pest infestations, we recommend installing 2 or more devices in other rooms. If you install devices in one room, they will not work in other rooms. Safe and Environmentally Friendly: Ultrasonic pest repeller contains no chemicals, is non-toxic, consumes less power, makes no sound, 100% safe for humans and pets, no need to clean up dead pests, no more calling a pest control technician for help Helps, no batteries required and can save a lot of money. Easy to Use: Simply plug this insect repeller into an outlet and perpendicular to the floor. The machine starts working when the blue light turns on. For areas with serious insect infestations, two or more types of ultrasonic insect repellents need to be used additionally. Generally speaking, it takes 3-4 weeks to take effect. Updated Ultrasonic Pest Repeller in 2023: The dual ultrasonic and electromagnetic chips of our ultrasonic pest repeller emit frequency ultrasonic waves that interfere with the hearing and nervous systems of pests, making them feel uneasy and uncomfortable, making pests, mice, rodents and Keep mosquitoes away from your home.