Lentek PR30-3M Ultrasonic Pest Repeller, 3 Pack Simply plug the lentek ultrasonic pest control device into an unobstructed wall outlet in the room to be covered by ultra-sonic sound power Economical single room protection offered by ultrasonic pest control 500 Single Speaker Design used in Ultrasonic Pest Control 500 Effective temporary relief from pests, (rats and mice) with the use of ultrasonic pest control 500 LED power indicator in ultrasonic pest control