1. It is a dual tube nostalgic special shape Led bulb, there is a T30 tube inside the T45 cylinder. T30 tube is with amber gold color glass, T45 cylinder is clear glass, so that we can see the two tubes clearly by different color. 255mm length led filament forms a dual spiral filament design. Both T30 tube and T45 cylinder is vacuum and helium gas filled in, same as normal vintage led bulbs.