In 2010 Volvo started offering what they called "Active gas Discharge" headlamps on P1 models. What they mean by "active" is that the headlamps can pivot with the steering to allow you to better see around corners.
The "active" gas discharge (xenon) headlamps use different bulbs than the regular gas discharge lamps. Some 2010 and newer models may have either style lamp.
If you have any of the following models you will need to check the style of bulb against the images on our site to ensure you order the correct one: