Check the listing for details. Xterminator Plug In Ultrasonic Pest and Rodent Repeller, 2 Pack. Color: White, Condition: New, Made in China. Listed at 17.99 USD. The Xterminator Ultrasonic Pest Repeller uses inaudible ultrasonic wave technology to combat unwanted rodents and pests. The high frequency ultrasonic waves effectively repel rodents and insects while being completely inaudible to the human ear. It's humane, driving the rodents away without killing them with harsh or toxic chemicals. The unit also minimizes human contact with mice, rats, or other disease-bearing rodents. It's easy to use, just plug in into the wall socket without anything blocking or covering the device and it's activated. Each device covers an open area of up to 1000 square feet eliminating Mosquitoes, Mice, Spiders, Ants, Flies, Roaches, Bugs, Fleas, Rats, etc. No batteries or maintenance required, and it's safe for use around children and most pets.