Mercedes-Benz C300 Dome Light Bulb Size

The Mercedes-Benz C300 dome light utilizes 6411 and 12961 bulb sizes for the interior lighting system. Data for the specific components covers the period from 2008 through 2014.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
2010-2014	6411
2008-2009	12961

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, 36mm length, SV8.5 base. 12V, 5W.	6411
Philips part number. Miniature wedge bulb (T10) with W2.1x9.5d base. 12V, 5W.	12961

Other Locations

Additional Notes

The Mercedes-Benz C300 dome light uses two distinct bulb types across its 2008-2014 model years: the 6411 and the 12961.
The 6411 is an ANSI-standardized bulb used in the United States and Canada, classified as a festoon type with a 36mm length and an SV8.5 base, rated at 12V and 5W.
Festoon bulbs mount by pressing their end caps into spring clips rather than inserting into a socket, which is a defining characteristic of the SV8.5 base format.
The 12961 is a Philips part number designating a miniature wedge bulb in the T10 form factor, fitted with a W2.1x9.5d base, also rated at 12V and 5W.
A wedge base bulb relies on the tension of its glass envelope and lead wires to seat within a socket, with no separate metal base or pins involved.
Although both bulb types share identical voltage and wattage ratings of 12V and 5W, their physical bases and mounting methods are incompatible with each other.
The Mercedes-Benz C300 (2010-2014) uses the 6411 festoon bulb for the dome light position.
The 2008-2009 C300 uses the 12961 wedge bulb for the same dome light position, representing a different fitment requirement from later model years.
The base type difference between the SV8.5 festoon and the W2.1x9.5d wedge means that bulbs from the 2008-2009 specification are not interchangeable with those from the 2010-2014 specification.
The 6411 designation follows ANSI standardization, meaning bulbs from multiple manufacturers carrying that number conform to the same physical and electrical specification.