Ultraviolet (UV) blacklight for detection of counterfeit bills, credit cards, identification cards, insects, and pet stains. Night clubs and bars use UV stampes where detection and authenticity is needed. Telescoping extending barrel allows for wide or narrow light beam. Longwave approximately 395 nanometers. Single CREE UV LED bulb. On/off button and strobing effect. 1 AA battery included & installed. Price includes laser engraving, engraves silver.