Latest technology and longer lasting effect - This ultrasonic pest repeller bombards the nervous system of most types of flying and crawling insects. Effectively bombards mosquitoes, spiders, bed bugs, cockroaches, mice, fleas, etc. Chemical-Free and Eco-Friendly - No chemicals or noise. The sound is not recognized by the ear and therefore does not disturb or stimulate people, cats and dogs. Our ultrasonic mouse/mouse repellent is harmless and safe for your family and pets. Does not harm your living environment. Ultimate Indoor Coverage - Our mouse/mouse repellent set contains 4 small but very powerful units. Each ultrasonic rodent repeller is small and quiet and covers up to 1700 square feet to protect your home, furniture, pets and family all year round. It is widely used in homes, warehouses, offices, gardens, hotels, etc. Easy to use : Simply connect the ultrasonic insect repellent to an outlet. Install our item 7-16 inches from the floor.