Perhaps someone could help me out. My job requires that I work outside at night (helicopter mechanic). For years I have used flashlights, but they were just tools, like a wrench or a screwdriver, I never thought much about them. Since arriving here I have become more interested in the workings of these tools. Is there any kind of reference material about Led's, the circuitry etc. which would be suitable for the layman? Also some kind of glossary for the jargon would help. What the heck is a bin? Thanks in advance. And hey, if you ever fly in a helicopter you can feel better that I saw any problems it might have had because I had my nitecore NDI, and not the 2D energizer bulb flashlight I used 30 years ago when I first started out!