D2R HID bulbs. The top bulb is from the driver's side and has caused no problems. The bottom bulb is opaque in the 'bulb' area just to the right of the gray band. This bulb would work for a long period of time, then 'wink off' requiring the headlights to be turned off, then on to re-light. It would do this several times in 15 minutes, then work fine for a long period again, then 'wink off' again. Don't know if the opaque section is an indicator of failure or not.