Get rid of mice, ants, spiders, roaches, rats and other pests safely-without using traps, dangerous chemicals or insecticides. This Bell + Howell® Pest Repeller uses ultrasonic signals that you can't hear, but drives pests out of your living space. Won't interfere with TVs, appliances or garage door openers. One unit per room. Comes with built-in AC auxiliary plug-won't block outlet. Each, 3 1/2"W x 3 3/4"H. UL-listed. Buy 1 Get 2 Free! Included in the package.