Mercedes-Benz B Electric Drive Dome Light Bulb Size

The Mercedes-Benz B Electric Drive dome light requires a 12961 bulb size for proper installation and function within the interior lighting system. Data for the specified vehicle covers the 2014 to 2015 range.

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
2014-2015	12961

Bulb Specifications

Description	Bulb Size
Philips part number. Miniature wedge bulb (T10) with W2.1x9.5d base. 12V, 5W.	12961

Other Locations

Additional Notes

The 12961 is a Philips part number designating a miniature wedge bulb in the T10 form factor, fitted with a W2.1x9.5d base and rated at 12 volts and 5 watts.
The T10 designation refers to the bulb's tubular shape, with the number indicating its width in eighths of an inch, making it one of the smaller wedge-base bulbs used in automotive interior applications.
The W2.1x9.5d base type is a wedge-style connection, meaning the bulb is held in place by tension from the socket rather than by a bayonet or screw mechanism.
At 5 watts, the 12961 operates at a low power draw, which is typical for dome and courtesy light applications where sustained illumination at low current is the primary requirement.
The Mercedes-Benz B Electric Drive (2014-2015) uses the 12961 bulb for its dome light across both model years covered in the specifications.
Because the W2.1x9.5d base is a standardized wedge fitting, physical interchangeability with other T10 wedge bulbs of the same base type is possible, though voltage and wattage ratings must match the 12V, 5W specification to ensure correct operation.