For the 2015 Audi S7, both the low-beam and high-beam headlights use integrated LED lighting. The supplied fitment data does not list a replaceable halogen bulb size or indicate a projector versus non-projector headlight variation, so confirm the complete headlamp assembly before ordering replacement parts.
Several other exterior lighting functions are also LED, including the front turn signals, daytime running lights, parking lights, cornering lights, brake lights, center stop light, tail lights, rear turn signals, license plate lights, and step lights. The reverse light uses a 921 bulb.
Side-marker fitment is listed as either 2825 or 98 for both the front and rear positions. Check the existing bulb and socket or verify the application before purchase, since these are the only supplied alternatives. No fog-light bulb fitment is provided for this model year.