Red Glass Glow in the Dark Spiral Tails (6 gauge - 7/16 inch)One Pair of Red Glow in the Dark Glass Spiral Tails. Additional Info: Glass is a hand made material so it can slightly vary in size, color, and shape. All of our glass pieces are guaranteed to be within 1mm of the stated size. If you need an exact measurement or better description of the item, feel free to email us before ordering. Glass is also a fragile material and can break if dropped or not handled correctly.