Safe to use: Ultrasonic Pest Repeller is human and pet friendly, keeping at bay all sorts of little enemies such as mice, rats, mosquitoes, flies, beetles, cockroaches, moths, ants, bedbugs and more. Wide coverage: The pest repellent gets coverage up to 15-30 m2. You should use one unit per a room to see the best result because the ultrasonic cannot pass through walls or solid objects. Indoor spaces that are suitable for this pest repeller plugin ultrasonic are house, garage, office, company, restaurant, warehouses, etc. REA:This ultrasonic insect repellent equipped dual microchip system and is suitable for the area of 15 to 30 square meters. Since ultrasound can not Penetrate through walls and solid objects, It is recommended to put one in one room. For areas where severe pests are severe, additional units are needed. Its widely used in homes, warehouses, offices, gardens, hotels, etc. We recommend you to install one for each room because the ultrasound cannot penetrate walls and solid objects. But for areas with serious pests, we suggest install 2 or more devices for other room. They aren't effective for other rooms if you install device at one room. Ultrasonic Pest Repeller no chemicals, less power consumption, inaudible and 100% safe to human and pets, no need to clean up dead pests, no more need to call pest control technician for help, no battery required and save a lot of money.