The Mercedes-Benz S400 parking light requires a 12961 bulb size for proper installation and function within the lighting assembly. Data for the specific component covers the range from 2010 to 2013.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mercedes-Benz S400 uses the 12961 bulb across all listed front parking light positions for the 2010-2013 model years.
The 12961 is a Philips part number designating a miniature wedge bulb in the T10 form factor, rated at 12 volts and 5 watts.
The T10 designation refers to a tubular bulb with a width of approximately 10 millimeters, commonly found in low-current auxiliary lighting positions such as parking lights.
The W2.1x9.5d base type is a wedge-style connector, meaning the bulb is held in place by the socket itself rather than by a separate locking mechanism or bayonet pins.
At 5 watts, the 12961 operates as a low-power incandescent source, consistent with its role in a parking light rather than a primary illumination function.
The uniform fitment of the 12961 across the 2010-2013 model years indicates that the front parking light socket specification did not change within that production span for the S400.
Because the 12961 is a Philips-assigned part number, equivalent bulbs from other manufacturers must share the T10 form factor, W2.1x9.5d base, 12V rating, and 5W output to be considered interchangeable.
The wedge base design of the W2.1x9.5d standard does not use metal contact pins, so fitment depends on the physical width of the bulb base matching the socket opening precisely.