SYLVANIA D1S HID High Intensity Discharge Lamp, (Contains 1 Bulb) HID lighting is light from a plasma discharge rather than a filament. HID uses less energy than halogen lighting, while producing 3 times more light. Light lasts up to 3 times longer than conventional halogen technology. OEM (Original Equipment Manufacturer) precision and quality for consistent performance. Compatible with existing D1S headlamp optics.