Now sure what HID bulb you need? Go to Philips Automotive Bulb Lookup website, enter your vehicle information, and the site will let you know all the bulb types your car or truck uses.
D1R D2R - use in REFLECTOR headlights
D1S D2S D3S D4S - use in PROJECTOR headlights
D2C D4C - use in PROJECTOR headlights - C designates UNIVERSAL fit so it can be substituted for D2S D4S. C series bulbs are mercury free and more power efficient.
D1R D1S D3S - have built-in igniters at the bottom of the bulb base
D5S - these HID bulbs are all-in-one bulbs with ballasts and igniters built-in. OEM D5S bulbs are only 25W. After-market D5S HID bulbs are 35W, making them 50% brighter than OEM.