Mercedes-Benz GL350 License Plate Bulb Size

The Mercedes-Benz GL350 license plate bulb uses 12961 and DE3423 size specifications for replacement bulbs. The replacement chart covers vehicle production years spanning 2010 to 2012.

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
2012	12961
2010-2011	DE3423

Bulb Specifications

Description	Bulb Size
Philips part number. Miniature wedge bulb (T10) with W2.1x9.5d base. 12V, 5W.	12961
ANSI standard (US & Canada). Festoon bulb, 41mm length, end-cap contacts. 12V.	DE3423

Other Locations

Additional Notes

The DE3423 is an ANSI-designated festoon bulb measuring 41mm in length with end-cap contacts, operating at 12 volts. Festoon bulbs seat by pressing lengthwise between two spring contacts 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, rated at 12 volts and 5 watts. The wedge base relies on the bulb's glass pinch being gripped directly by the socket contacts, with no separate metal base component.
The Mercedes-Benz GL350 uses two distinct and physically incompatible bulb types across its 2010-2012 model years for the license plate position. The DE3423 festoon and the 12961 T10 wedge cannot be substituted for one another due to their different base configurations and socket designs.
The 2010-2011 GL350 specifies the DE3423 festoon bulb for the license plate position, while the 2012 model year specifies the 12961 T10 wedge bulb. This indicates a socket design change occurred between the 2011 and 2012 model years.
The DE3423 designation follows ANSI standards applicable in the United States and Canada, meaning the bulb conforms to a standardized specification rather than a single manufacturer's proprietary numbering system.