Mercedes-Benz ML350 Dome Light Bulb Size

Additional Notes

• The Mercedes-Benz ML350 dome light specifications cover model years 2003 through 2011, with two distinct bulb types used across that span depending on the generation of the vehicle.
• The 6411 is an ANSI-standardized festoon bulb with an SV8.5 base and a 36mm length, operating at 12V and 5W. Festoon bulbs seat at both ends within spring-clip holders rather than inserting into a socket, which is a fundamentally different mounting method from wedge-type bulbs.
• The 12961 is a Philips part number designating a T10 miniature wedge bulb with a W2.1x9.5d base, also rated at 12V and 5W. The wedge base relies on friction and contact pressure within a dedicated socket rather than end-clip retention.
• Because the 6411 and 12961 use physically incompatible base types, one cannot substitute for the other despite sharing identical voltage and wattage ratings.
• The ML350 (2003-2006) uses the 6411 festoon bulb for dome lighting.
• The 2007 ML350 also uses the 6411, placing it within the same bulb fitment as the earlier model years in that generation.
• The ML350 (2008-2011) transitions to the 12961 wedge bulb, and the specifications designate this fitment specifically as the rear dome position.
• The positional label "Rear" associated with the 12961 in the 2008-2011 entries indicates that this bulb applies to the rear dome light location within the cabin.
• The W2.1x9.5d base designation on the 12961 describes a wedge-type contact system where the bulb glass itself, rather than a separate metal base, forms the electrical connection through its pinched leads.
• Both bulb types share a 5W power draw, which places them in the low-output category typical of interior courtesy lighting rather than task or reading illumination.