Window Alerts Butterflies

Now you can help reduce the huge number of birds killed each year flying into windows. WindowAlert is a static cling decal that's easily applied to windows at home, at the office, on greenhouses, conservatories or anywhere that glass may creat an invisible and fatal obstacle. The decals contain a component which reflects ultraviolet sunlight undetectable to humans, it glows brightly for birds to spell out danger ahead! Pack of 4 decals, each about 10.2cm 4 diameter. 1 decal is sufficient per msup2.