The low-profile Balcony Gard uses quiet ultrasonic sounds to repel annoying birds from small outdoor areas around the home! The Balcony Gard is a safe, effective, humane repeller for birds that invade your property. It creates an ultrasonic sound wave that repels these birds without chemicals, traps, or poisons while still being silent to most humans. Set it to continuous use or motion-activated mode and keep pest birds away. Protect cars, property, and landscaping from corrosive bird dropping damage!