WindowAlert Classic Square UV Decal helps prevent wild birds from accidentally flying into your windows by using a special coating that reflects ultraviolet sunlight. This UV reflection is invisible to humans but appears as a bright glow to birds, similar to a stoplight, effectively warning them away. To install, simply place the decal on the outside of your window, starting at the center and working outward. It is to place decals at least every 2 feet of glass, with scientific studies suggesting spacing them 2 inches horizontally and 4 inches vertically for maximum protection. This innovative solution combines safety for birds with ease of use and discreet design. Model Number: