BirdXPeller Pro keeps birds from infesting large open areas-up to one acre. Uses birds’ own distress calls to create a “danger zone”Bird-X Peller Pro comes in two different models the Pro-1 and the Pro-2. Please specify when ordering. Model 1 is for pigeons, swallows, gulls, and woodpeckers. Model 2 is for crows, blackbirds, and geese.