WindowAlert decals and WindowAlert UV liquid have a coating that brilliantly reflects ultraviolet sunlight. This coating will slowly degrade when exposed to the elements (wind, rain, snow, and sunlight).
This 395 nanometer LED UV black light flashlight can be used to test the quality (or fading) of WindowAlert products. Simply shine the light on your WindowAlert decals or UV Liquid . . . at night. New products will reflect brilliantly. Old or faded products will not reflect.
Four AAA batteries not included.