UV (Ultra Violet) light, also known as “black light,” emits electromagnetic radiation almost exclusively in the soft near ultraviolet range causing some items to fluoresce. White clothes, teeth, etc. glow in the dark while other objects look exciting and unusual depending upon how much they reflect UV. This Chauvet Handheld Blacklight / Flashlight is an ideal size for night clubs, theme parks or any other secure entry business. It's also great for authentication of antiques, paintings or documents, as well as viewing marked bank notes and other valuable objects. The blacklight runs on 4 AA batteries (purchased separately).