The BirdXPeller Pro uses actual species-specific distress cries and can be set for any or all of a variety of birds including pigeons, sparrows, starlings and gulls. Volume, time-off periods, and random calls can be varied to keep the birds away. The unit measures 10" x 3" x 10" and weighs 4 lbs. The directional speakers cover up to an acre in an oval pattern. The unit comes with an AC adapter cord but can run off a 12 volt DC battery if needed.