The Mercedes-Benz R500 parking light requires a bulb size of 12961 for the lighting system. Data for the specified component covers the range from 2006 to 2007.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mercedes-Benz R500 uses the 12961 bulb for the front parking light across the 2006-2007 model years.
The 12961 is a Philips part number designating a miniature wedge bulb in the T10 form factor, which is one of the most widely used bulb types in automotive parking and interior lighting applications.
The T10 designation refers to the bulb's tubular shape, with the number indicating its width in tenths of an inch, making it a compact form factor suited to low-profile housings.
The 12961 operates at 12 volts and 5 watts, which is characteristic of low-current indicator and parking light applications where heat output and power draw are kept minimal.
The base type for this bulb is the W2.1x9.5d, a wedge-style base that relies on tension from the socket rather than a bayonet or screw mechanism to maintain contact and retention.
The W2.1x9.5d base is not interchangeable with bayonet or festoon bases, and substituting a bulb with a different base type would result in an improper fit within the R500's front parking light socket.