Check out this LED UV Penlight

[fenix store]

A penlight is already one of the most useful tools you can carry — and it's small enough to bring wherever you go. But the new LD02 V2.0 EDC LED Penlight takes this functionality one step further with the addition of an ultraviolet (UV) light source.​ ​ ​ ​

Who Should Carry a UV Light?​

Invisible to the naked eye, UV light can be used to detect counterfeit money, making it useful to anyone whose work involves handling cash. Law enforcement and other professionals rely on UV light to detect bodily fluids such as blood or urine, as well as mold and mildew. If you're a frequent traveler, consider using a UV flashlight to inspect surfaces in your hotel room for cleanliness. ​