All I know is years ago I got some of the plastic fiberoptic; wish I could find a new source for it as it's *very* neat stuff to work with. The stuff I got is maybe .04" dia or so. You can do a couple of tricks with it too, like hold the end next to (not in) a candleflame and it will melt a perfect sphere on the end. Put this near a light source and the brightness at the other end goes waaay up. Another trick: drill holes and thread the fiberoptic thru them, then heat the ends and they won't slip out. I've made "billboards" this way that flash things like "Eat at Joes", etc. Fun stuff.