DX610 Pest-A-Repel. Electronic Ultrasonic Pest Repeller STOPS Mice and Rats from nesting. Drives then OUT of hiding FAST! Once you see or hear evidence that you have a mouse or rat problem, you need to act quickly BEFORE they start to NEST. AUTOMATICALLY changes volume and sound patterns to PREVENT rodents from getting use to the sound waves or the DX610 frequency levels. AUTOMATICALLY changes frequency range from 40,000 to 45,000 Hz for QUICKER erradication and wider selection of unwanted pests. Industrial Grade Quality. Recommended for both Commercial and Residential use. Covers up to 2500 Square Feet per floor. Safe for humans and non-rodent pets like your family cat, dog, bird, horse, fish, snake. SOME advertised products use lower frequencies that CAN be heard and felt by people.