This is Firefly Glass, It's designed by NOGU Studio in Toronto. Nope, there are no electronics involved. The bracelets are made of genuine lampwork hand-blown glass and once energized under a light source emit a spectacular glow. They are the grown up luxury version of your favorite glowing baubles as a kid. During the blowing of the glass, small phosphorescent particles are suspended inside the glass and when charged explode with a brilliant emerald glow. HOW TO CHARGE 1) Supercharge your Firefly Glass in seconds with our NOGU Ultraviolet Light for a lightning fast glow that emits more phosphorescence and lasts longer than any other charging method. 2) Charge under a bright lamp for up to 5 minutes. The stronger the light source, the brighter the phosphorescent glow! 3) Charge in the sun near a window. Place the bracelet in a bright sunbeam and let the bracelet charge up to 10 minutes. The brighter the natural light beam, the brighter the phosphorescent glow! Open to offers!