All window films typically have a list of ratings attached based on a variety of measurements. This is one of the most accurate ways to determine what the film will do for you once you put it on your windows. While you probably won't know what a few of them mean, for most consumers there are only a few that are relevant and informative. Regardless, this article will help define these specs and help you understand what to look for when choosing a window film. Visible light reflectance is the amount of light reflected away by the film.