The Pestrol Triple High Impact Mice, Rat, Rodent Repeller comes to do its job. It utilizing 3 speakers that maximize rodent-repelling results, such as Mice, Rats, etc. Our specially designed speakers transmit ultrasonic sounds at three different locations on the device. All of these speakers do a specific job and transmit/repel in different ways causing what we like to call the Triple Attack Design. In most cases, rodents leave with-in a 12 - 16 day period. But sometimes when a stubborn rodent problem comes along and you're having troubles that are when we take pride on being very helpful so repelling results get met.