CoolVu Window Films “transition” from a lighter to a darker tint when exposed to sunlight. On bright sunny days, CoolVu reacts to the sun’s intensity and darkens to reduce sun glare and heat gain. On cloudy, rainy days and at night, CoolVu remains unchanged preserving your views and maximizing available daylight. With this unprecedented technology, you will see improved occupant wellness, adaptive glare control, protection from UV radiation, and reduce solar heat gain.