The Mercedes-Benz R320 parking light requires a bulb size of 12961 for the lighting assembly. Data for the specific component covers the range from 2007 to 2009.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 2007-2009 Mercedes-Benz R320 uses the 12961 bulb for the front parking light position.
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 body approximately 10mm wide, a standard sizing convention in automotive miniature lighting.
The W2.1x9.5d base specification describes a wedge-type connection where the glass envelope itself acts as the retention mechanism, requiring no separate metal base or socket pins.
At 5 watts, the 12961 operates within the low-wattage range typical of parking and position lights, which are designed for continuous illumination rather than high-intensity signaling.
The W2.1x9.5d base is a specific wedge standard, and substituting a bulb with a different wedge base designation risks an improper fit within the R320 socket.