Size: The size of each bird repellant windmill's diameter is 20 cm/7.87 inch, and the total length is 52 cm/ 20.47 inch. How It Works: The reflection of light (or the reflective rotation of two sides of different colours) confuses the bird's vision. In windy conditions, the bird repellant also makes some noise and keeps birds from moving away from the area. Beautiful garden helpers: These bird repellers are great for farmers and gardeners to keep birds away from your garden effectively, these bird repellers for yards and gardens can scare away birds and can be installed anywhere to beautify your environment and protect your vegetables or fruits. Safe Bird Scarer: These pinwheels dazzle the birds by reflecting the strong light, while the windmill rotates in the breeze to make a metallic sound, scaring birds from adapting to the environment and flying away. No damage to birds and the environment. Scope of Application: These bird reflective pinwheels feature both practical and decorative functions, you can simply insert the bird repellant pinwheels directly into the lawn/plant pots, and can prevent your gardens, crops, windows, boats or cars from bird damage effective, scare other small animals away, meanwhile, make your house more beautiful.