The listing, Blue fiber optic hair extension has ended.
Looks amazing in hair when its dark enough to really let the light stand out. Worn once for a couple hours at a party before I cut my hair. Runs on button battery. I would say that the only downfall is the little plastic tab used to turn it on and off. To turn it on, tab must be removed, to turn off, must be put back. Since its only half an inch long, its hard to keep track of. So, if you get it, make sure you keep the tab in your wallet or somewhere you will not lose it while it is in your hair.