Mercedes-Benz C43 AMG front side marker bulbs use 2357NA size while rear side marker bulbs use 12821 size. The replacement chart covers 1998 to 2000 model production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mercedes-Benz C43 AMG uses two distinct bulb types across its front and rear side marker positions for the 1998-2000 model years, with each position requiring a different bulb entirely.
The 2357NA is an ANSI-standardized bulb recognized in both the United States and Canada, meaning it follows a regulated specification rather than being proprietary to a single manufacturer.
The 2357NA is a dual-filament bulb, which means it contains two separate filaments operating at different wattages within a single housing, rated at 26.9W and 8W on a 12V circuit.
The 2357NA uses a BAY15d bayonet base, a two-pin offset bayonet mount that is designed to prevent incorrect insertion by positioning the two pins at different heights along the base.
The natural amber glass of the 2357NA produces its amber color through the glass itself rather than through a coating or lens filter, which is the defining characteristic of the "NA" designation in the part number.
The front side marker position on the C43 AMG (1998-2000) uses the 2357NA across all three model years without variation.
The 12821 is a Philips part number designation for a miniature wedge bulb of the T10 type, operating at 12V with a 5W rating, making it significantly lower in wattage than the front marker bulb.
The W2.1x9.5d base on the 12821 is a wedge-style base, which is held in its socket by the tension of the socket contacts rather than by a locking mechanism such as a bayonet fitting.
The rear side marker position on the C43 AMG uses the 12821 across the 1998-2000 model years without variation.
The 2357NA and 12821 are not interchangeable, as they differ in base type, filament count, wattage, and physical form factor.