5 pc UV LED Flashlight Mini Keychain ID Currency Detector Ultraviolet Purple Easily identify invisible ink, authenticate currency, driver's license, identification cards, passports, scorpions, official documents, etc. Essential tool for security, law enforcement, postal inspections, customs, medical forensics, HVAC repair Find dried urine stains from dogs, cats, and other pets on carpet, rugs, clothes, bathroom, etc. Also detect food stains on floor or table. Fluoresces at distances over 8 feet in darkness with 1 bright UV LED bulb. Each light contains three AG3 batteries installed and tested.