Mercedes-Benz SLK350 front side marker bulb uses size 12961 while rear side marker bulb uses size 67. Replacement chart covers 2005 through 2011 production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mercedes-Benz SLK350 front side marker uses the 12961 bulb across the 2005-2011 model years.
The 12961 is a Philips part number designating a T10 miniature wedge bulb with a W2.1x9.5d base, rated at 12V and 5W.
The T10 wedge form factor requires no locking mechanism, as the base itself wedges into the socket to maintain contact.
The rear side marker on the SLK350 uses the 67 bulb for the 2005-2006 model years.
The 67 is an ANSI-standard designation recognized in the US and Canada, featuring a single filament and a BA15s bayonet base, rated at 12V and 8W.
The BA15s bayonet base uses a single locating pin, which distinguishes it from the dual-pin BA15d base and makes the two physically non-interchangeable.
The 67 bulb is a lower-wattage variant of the 1156. Although the two share the BA15s bayonet base, their wattage ratings differ, and substituting one for the other may affect circuit compatibility.
The front and rear side marker positions on the SLK350 use different bulb types with different base designs, meaning the two are not interchangeable with each other.