Bird-X Balcony Gard Ultrasonic Bird Repeller BEST-SELLING Residential Electronic Bird Repeller. Sound Pressure-90 dB at 1 meter. Frequency Range-15 to 25 kHz (adjustable). Working Current-less than 200 mA Adjustable settings, offers up to 900 square feet of coverage Silent to most humans, safe, humane, easy to operate, and effective; harmless to children and pets Battery operated with A/C option--includes 50-foot extension cord Keeps pest birds off your balcony, porch, or deck!.Please refer user manual attached below for instructions and troubleshooting steps BEST-SELLING Residential Electronic Bird Control Device Efficiently works to deter pest birds Eliminates clean-up, damage caused by birds Humane and harmless to children and pets Effective coverage in covered areas up to 900 sq. ft.