No not that kind of nail! A fake acrylic finger nail! after taking my bits and pieces home, I experimented with gluing a red LED to back of some of the nails. It work amazingly well and after applying power, the nail was very brightly lit. Now some engineering questions started happening. If someone glues one of these to their finger, they can't exactly take a shower with the battery attached, so i needed to come up with a connector that was small, robust and above all... pretty! what i came up with is the small the connector commonly used on wifi and bluetooth modules called a U.FL connector. It had golden contacts (pretty!), it was small and easy to use....