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. They are handcrafted in Stainless Steel & beautifully gift boxed. They are the perfect summer accessory and are guaranteed to add some light to your day (or night!)