Mercedes-Benz SLK230 Dome Light Bulb Size

The Mercedes-Benz SLK230 dome light requires bulb size 6411 or H6W depending on the specific version of the vehicle. Data for the bulb sizes covers the range from 1998 through 2004.

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
2004	H6W
1998-2003	6411

Bulb Specifications

Description	Bulb Size
ECE standard (Europe & worldwide). Single-filament signalling bulb with BAX9s base. 12V, 6W.	H6W
ANSI standard (US & Canada). Festoon bulb, 36mm length, SV8.5 base. 12V, 5W.	6411

Other Locations

Additional Notes

The Mercedes-Benz SLK230 dome light uses two distinct bulb types across its model years, with the 6411 fitted to the 1998-2003 models and the H6W fitted to the 2004 model.
The 6411 is an ANSI-standard festoon bulb operating at 12V and 5W, with a 36mm length and an SV8.5 base, a socket type common in North American automotive applications.
The H6W is an ECE-standard bulb operating at 12V and 6W, with a BAX9s base, a bayonet-style cap used widely in European and international vehicle markets.
The BAX9s base of the H6W is offset-pin bayonet, meaning it is not interchangeable with standard BA9s bases despite the physical similarity in size.
The 6411 and H6W differ in both base type and wattage, making them incompatible with each other without a socket adapter.
The shift from the 6411 to the H6W between the 2003 and 2004 SLK230 model years reflects a change in the applicable bulb standard for that position.
The SV8.5 base of the 6411 is a festoon-style contact system where the bulb is held by spring clips at each end rather than inserted into a keyed socket.
At 6W, the H6W draws slightly more power than the 5W 6411, a relevant consideration when assessing socket and wiring compatibility during a bulb replacement.