Mercedes-Benz CLS550 License Plate Bulb Size

The Mercedes-Benz CLS550 uses a DE3423 bulb for the license plate lighting component located at the rear of the vehicle. Data for the specific bulb size covers the period from 2007 through 2011.

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 Type	Shop
2007-2011	DE3423	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Festoon bulb, 41mm length, end-cap contacts. 12V.	DE3423	Check Price

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Additional Notes

The Mercedes-Benz CLS550 uses the DE3423 bulb for the license plate position across the 2007-2011 model years.
The DE3423 is a festoon-type bulb, meaning it is cylindrical in shape and makes electrical contact through metal caps at each end rather than through a base socket or pins.
The DE3423 has a length of 41mm, which is the critical fitment factor for festoon bulbs, as the housing retains the bulb by tension between its two end contacts.
The bulb operates at 12 volts, consistent with standard automotive electrical systems.
The DE3423 designation follows ANSI standards recognized in both the United States and Canada, indicating the bulb conforms to a defined set of performance and dimensional criteria shared across those markets.
Because festoon bulbs are retained by length rather than by a keyed base, substituting a festoon bulb of a different length risks poor contact, intermittent illumination, or failure to seat properly in the housing.