Visual Bird, Woodpecker, Swallow Repellent (Patent Pending). Qty 10. Fluttering, colors and sounds mimic the strike movements of predatory birds. Possibly the easiest yet most effective method of reducing or eliminating expensive woodpecker damage, swallow nesting behavior, and crop losses in vineyards etc. No batteries, cords, or other maintenance requirements. Small 2×6 inch reflectors are wind operated, easy to install and durable. Comes ready to install with manufactured support wire, use nails or screws, not included. Directions included. You must hang one on each corner of the house so birds will not move to another side of house where they do not see the Flasher. This product is the best bird repellent there is by far!