The Mercedes-Benz SLK280 front turn signal bulb size measures 3357NA or 3457NA, while rear turn signal bulb size measures PY21W, 12496, or 1156NA. The replacement chart covers 2006 to 2008 model 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 SLK280 front turn signal uses two different bulb types across its model years: the 3357NA for 2008 and the 3457NA for 2006-2007.
The 3357NA and 3457NA are both T25 wedge bulbs operating at 12V under the ANSI standard used in the US and Canada, but they differ in filament count. The 3357NA is a single-filament bulb rated at 27W, while the 3457NA is a dual-filament bulb rated at 27W and 7W.
Because the 3357NA and 3457NA share the same T25 wedge base and voltage rating, physical fitment may be possible across both types, but their filament configurations differ, which affects how the bulb functions in the circuit.
Both the 3357NA and 3457NA feature natural amber glass, meaning the amber color is produced by the glass coating rather than by a colored lens or housing.
The rear turn signal of the SLK280 uses a different bulb for each of its three model years, with no shared fitment across 2006, 2007, and 2008.
The 2008 rear turn signal uses the PY21W, an ECE-standard bulb with a BAU15s bayonet base rated at 12V and 21W. The BAU15s base has an offset pin that prevents substitution with the BA15s base used on the 1156NA.
The 1156NA, specified for the 2006 rear turn signal, uses a BA15s bayonet base and is rated at 12V and 21W. It carries natural amber glass and falls under the ANSI standard.
The 12496, specified for the 2007 rear turn signal, is a Philips/Osram part number designation rather than an ANSI or ECE standard number, indicating it is a proprietary or specialty halogen bulb rated at 12V.
The base types across the three rear turn signal bulbs, T25 wedge, BAU15s bayonet, and BA15s bayonet, are physically incompatible with one another, meaning rear turn signal bulbs are not interchangeable across the 2006-2008 model years.
The PY21W follows the ECE regulatory standard, which is common in European markets, while the 3357NA, 3457NA, and 1156NA follow the ANSI standard associated with North American markets.