Evict rats, mice, cockroaches, spiders, scorpions and other pests from rooms large and small within two weeks with this easy-to-use ultrasonic pest repeller from Black & Decker. The unit emits ultrasonic sounds pests can’t stand. A 100- percent Duty Cycle means constant sound so, once they’re gone, critters get no chance to come back. The unit works by disrupting pests" nervous systems, affecting both feeding and communication. The frequency ranges from 26 to 74 KHz at 105 decibels in a constant fluctuation so pests can’t adapt to the constantly changing array of complex ultrasonic and sonic sounds. SAFE for use around humans, dogs, cats, birds and fish, the repeller should be kept well away from pet tarantulas, mice, hamsters, gerbils and rabbits. User-friendly Controls let you adjust settings on unit"s back to repel specific pests. The unit works in extra large rooms, operating from any flat surface with better results achieved by moving the unit to different locations. Continue use once pests leave. The purchase includes 120V AC adapter.