The Mercedes-Benz SLK230 tail light utilizes bulb sizes 67 and 12821 for the rear lighting assembly. Data for the specific components covers the period from 1998 through 2004.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mercedes-Benz SLK230 outer tail light uses two distinct bulb positions, each with its own size specification that varies by model year.
The 1156 is an ANSI-standard single-filament bulb with a BA15s bayonet base, rated at 12V and 21W. It serves the outer tail light on the SLK230 from 2001-2004.
The BA15s bayonet base features a single contact pin, which distinguishes it from dual-filament bayonet bases and makes it non-interchangeable with those types.
The 12961 and 12821 are both Philips part numbers designating T10 miniature wedge bulbs with a W2.1x9.5d base, each rated at 12V and 5W. Despite carrying different part numbers, their electrical and physical specifications are identical.
The second outer tail light position on the SLK230 uses the T10 wedge bulb across all model years from 1998-2004, with the 12821 fitted from 1998-2003 and the 67 fitted in 2004.
The bulb 67 is an ANSI-standard single-filament bulb sharing the BA15s bayonet base with the 1156 but rated at a lower 8W rather than 21W. The two are not electrically interchangeable despite sharing the same base type.
The outer tail light on the SLK230 transitions from the 12961 to the 1156 between the 2000 and 2001 model years in its primary position, representing a change from a 5W wedge bulb to a 21W bayonet bulb.
The W2.1x9.5d base used by both the 12961 and 12821 is a wedge-type connection with no pins, relying on the tension of the socket contacts against the bulb's wire leads for electrical contact.