What is HID High-intensity Discharge (HID) lamp ia a new type of lighting technology that replaces the conventional halogen lamps with electrodes. It uses electrical discharge techology to ignite inert gas contained in a sealed bulb inside. HID lamps Adventages High-intensity brightness 3 times brighter than halogen lamp. Longer Life: Last 2500 hours or more. Power saving: Only 35W. Attractive light color. Attractive & comfortable light including 5000K, 6000K, 8000K, 10000K, etc. KIT Composition HID conversion kit is composed of HID lamps, ballasts and installation accessories which are used to retrofit the conventional halogen headlamp system into the HID xenon headlamp system. HID lamp: 2 pieces. Ballast: 2 pieces. Accessories: one set.