15000hz, 17500hz & 20000hz Ultrasonic Ultimate Extreme Mouse And Rat Repellent (11 1/2 Hours) -

Sound waves at these frequencies do not travel through walls or furniture. For the best results, place the speakers in the open, directed toward the area where activity is highest.

Use the audio consistently for several nights. Ultrasonic repellents are most effective as a "slow burn" deterrent rather than an instant fix. Sound waves at these frequencies do not travel

Mice and rats have a much broader hearing range than humans, extending well into the ultrasonic spectrum (up to 70–90 kHz). place the speakers in the open