This is a Arc AAA light that I stripped the HA III anodizing off of using a LYE solution.  The light was thin polished with Flitz to a nice bare AL shine.  Clay was placed over the ends of the head to prevent the LYE from getting to the LED and electronics.

This is an old, cheap Rayovac 2D light, that I cut down to 1D size.  It now holds an Arc AAA head like the one above.  It has a runtime of 60+ hours.