Vermeil: 18k White Gold Beads: Authentic Firefly Glass Cord: Clear Elastic Cord Size: 7.8" Circumference Base: .925 Sterling Silver Time to #GLOWUPThis 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 .925 Sterling Silver & beautifully gift boxed. They are the perfect summer accessory and are guaranteed to add some light to your day (or night!)Surprise someone with a #noguglowup⚡⚡ 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! NOTE: All firefly glass beads are artisanal & handblown. As a result, minor variation in bead shape or size may occur.