The Mercedes-Benz ML550 parking light requires a bulb size of 12961 for the specific lighting component located on the front of the vehicle. Data for the bulb size covers the range from 2008 through 2011.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mercedes-Benz ML550 uses the 12961 bulb for the front parking light across the 2008-2014 model years.
The 12961 is a Philips part number designating a miniature wedge bulb in the T10 form factor.
T10 refers to a tubular bulb with a nominal width of 10/8 of an inch, commonly used in low-intensity automotive lighting positions such as parking lights and courtesy lights.
The 12961 bulb uses a W2.1x9.5d base, which is the standard wedge-type base where the electrical contacts are made through the glass pinch at the bottom of the bulb rather than through metal pins or a bayonet fitting.
The bulb operates at 12 volts and 5 watts, placing it in the low-wattage category typical of indicator and parking light applications.
Because the 12961 is a Philips-branded part number, equivalent bulbs from other manufacturers are cross-referenced under different part numbers but share the same T10 wedge base and 12V/5W electrical rating.
The W2.1x9.5d base designation is standardized under international automotive bulb classifications, meaning fitment is determined by base geometry rather than brand, provided the voltage and wattage ratings match.
Substituting a bulb with a higher wattage rating than 5W in a socket rated for this specification risks exceeding the thermal tolerance of the socket housing.