I scrounged some red LEDs from bike lights I've found (when the snow melts they are all over the place).
LEDs are cheap, but I'm cheaper and I like to "recycle" components.
But some of these LEDs are a bit annoying. They look like normal clear plastic LEDs, but the leg connected to "the smaller piece of metal" inside it is not the positive, but the negative leg! It has a flat side that correctly denotes the negative leg, but they have fooled me a couple of times anyway.
Do any of you know more about these? Is there a good reason or is it just a production error that has been sold to the bike light factory?