The Bell + Howell Ultrasonic Plug In Pest Repellers delivers powerful, nontoxic, and chemical free pest control for any home. These electronic pest control devices use advanced multi frequency ultrasonic sound waves to help deter mice, rodents, ants, spiders, cockroaches, mosquitoes, and other insects. Each unit includes a soft LED indicator light and a compact 2.5 inch wide by 3.25 inch tall design ideal for kitchens, hallways, bedrooms, attics, and basements. Perfect for DIY pest control, each repeller protects one room with silent, odorless operation. Safe for families and pets with no poisons or fumes. Available in 2 pack, 3 pack, and 4 pack options for complete home coverage and continuous 24 hour protection.