Awesome tool for light painting in photography. Gives a really rich, deep blue wash over subjects and the button is easy to click on and off quickly.

I do non-destructive testing and we use blue light to check for magnetic particle fluids on metal parts. This little flashlight is surprisingly powerful for its size and easily outperforms the expensive brand-name ones my company provides. I just charge it in my truck between jobs.

If you're a mechanic trying to find an oil or AC leak with dye, you need to try a blue light. The car guys on Reddit mentioned blue light sometimes works better than UV for specific automotive dyes, and they were dead on. Found the AC leak on a Honda in literally two minutes. Plus, it’s waterproof so I don’t worry about dropping it in coolant puddles under the lift.