Your belly button ring containing special material receives this light and when the time of darkness comes it begins to glow. It looks interesting, surprising and stunning. By the way it's not bad navigation system for cheerful persons. Glow in the dark skeleton navel ring is rather symbolic and makes the atmosphere of night around you more tense and mysterious. We are glad to offer glowing flexible navel rings for pregnant women. If you want to make your night life more light and various glow-in-the-dark belly button ring is probably what you need.
See also
UV Belly Button Rings