Flashlights utilizing special wavelenghts for specific CSI, fluorescense, & curing applications. Flashlights utilizing UV LEDs and other wavelengths are used for detection of inks, dyes, and other materials that fluoresce under UV or specific wavelengths of light, including 365, 375 and 395 nm (nanometers). Ultraviolet (UV) LEDs emit light energy in the near UV range commonly known as "black light." Flashlights utilizing UV LEDs are used for detection of inks, dyes, and other materials that fluoresce under UV light. Applications include: A/C refrigerant leak detection, adhesive curing, antique inspection, art forgery/repair tests, club hand stamp screening, fluorescent dye leak detection, glass inspection, body fluid tracing, ID and document verification, mineral lighting and identification, pet and pest stains, reading invisible fluorescent inks, scorpion illumination, fruit spoilage, and orange crop freeze damage (365nm).