Mercedes-Benz SLK350 Dome Light Bulb Size

The Mercedes-Benz SLK350 dome light utilizes bulb sizes 12961 and H6W according to the provided technical specifications for the interior lighting components. Available data covers the range from 2005 through 2011 for the specified vehicle and lighting application.

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
2007-2011	12961 (Front)
2005-2006	H6W

Bulb Specifications

Description	Bulb Size
Philips part number. Miniature wedge bulb (T10) with W2.1x9.5d base. 12V, 5W.	12961
ECE standard (Europe & worldwide). Single-filament signalling bulb with BAX9s base. 12V, 6W.	H6W

Other Locations

Additional Notes

The Mercedes-Benz SLK350 front dome light uses two distinct bulb types across its model years, with the H6W specified for 2005-2006 and the 12961 specified for 2007-2011.
The 12961 is a Philips part number designation for a T10 miniature wedge bulb operating at 12V and 5W, fitted with a W2.1x9.5d base.
The H6W follows ECE (Economic Commission for Europe) standards, making it a globally recognized specification rather than a manufacturer-specific part number.
The H6W is a single-filament signalling bulb rated at 12V and 6W, seated in a BAX9s base, which is a offset pin bayonet fitting distinct from standard bayonet caps.
The T10 wedge base of the 12961 and the BAX9s bayonet base of the H6W are physically incompatible socket types, meaning the two bulbs are not interchangeable despite their similar voltage ratings.
The 1W difference between the H6W (6W) and the 12961 (5W) reflects a minor output variation, though the differing base types remain the primary fitment distinction between the two generations.
The W2.1x9.5d base designation on the 12961 describes a wedge-type contact system, where the bulb is held in place by the socket walls rather than by a locking pin or bayonet mechanism.
Both bulb types share a 12V operating voltage, consistent with standard 12-volt automotive electrical systems.