Easy to use, easy to forget plug-in pest control device. Just plug it in – effectively chases away pests in home or office. Effective on rodent pests like mice & also insects like spiders, ants & cockroaches. Safe for use around children & pets. No poisons, chemicals or traps. Use anywhere pests are seen. Ideal for basements, garages, attics, crawl spaces, barns, sheds. Covers average size rooms; use more units for large spaces or in rooms with a lot of furniture. 4 units per 4 Pack. Uses Ultrasonic, silent technology. 220V 2-prong plug for standard 220V outlet. Each pest-x unit covers 50 square meters.