Help prevent wild birds from accidentally striking windowsMillions of birds die each year when they fly into the reflection of sky, clouds and trees they see in our windows. Each decal has a special coating that reflects ultraviolet sunlight. This ultraviolet light is invisible to humans, but birds see it as a brilliant glow much like a stoplight. Place decals on the outside of the window. Concentrate decals at center then work out, placing decals at a minimum, on every 2 feet of glass. UV coating will fade based on exposure and local elevation. For best results, replace decals every 4 months. Approximately 4 inches, 4 per package. Decals are static cling design. Square WindowAlert Decals, set of 4 Save your birds' lives with ultraviolet window decals Features translucent design, so you can still see out your window Made in the USA
