For the 2008 Porsche 911, the low-beam headlight uses a D1S bulb. High-beam fitment depends on the headlight type: use H9 with halogen headlights or H11 with HID headlights. Confirm the headlight configuration before ordering, since these high-beam bulbs are not interchangeable fitment listings.
Other notable lighting options include two listed front turn-signal bulbs, 7507 and 2827. The brake and tail lights may use either 7225 or 7528; compare the replacement with the original bulb before purchase. The center stop light is listed as LED.
For replacement reference, the reverse light uses 7506, the license-plate light uses 6418, and parking or front side-marker applications list 2825 or 98. Interior listings include 2886X for the map light, with additional 6411, 6428, 2825, or 98 applications depending on location.