For use in average sized rooms, kitchens, garages, attics and basements Emits high frequency sound waves that effectively repel rodents Sound is completely inaudible to people and non-rodent pets Varying ultrasonic sound waves prevents rodents from getting used to the Victor Sonic PestChaser Since the sound is inaudible, a red LED light shows unit is working properly Reduction in rodent activity should occur within 6-10 days Multiple units required for multiple rooms