90-watt Low Pressure Sodium (LPS) High-Intensity Discharge (HID) light bulb. These highly efficient, tubular bulbs emit an intense monochromatic yellow-orange light (around 1700K to 1800K) and are traditionally used for streetlights, roadways, tunnels, bridges, and security area floodlighting. Because major manufacturers like Philips have largely discontinued traditional low-pressure sodium lamps, they are increasingly difficult to source, though third-party replacements and LED retrofit options are available.