Mercedes-Benz GL350 Turn Signal Bulb Size

The Mercedes-Benz GL350 front inner turn signal uses a 3457NA bulb size, while front turn signals accommodate PY24WNA, 3457NA, or 12961 bulbs, and rear turn signals require PY21W or 12496 bulbs. The replacement chart covers 2010 through 2016 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.

Front Inner Turn Signal

Years	Bulb Size
2010-2012	3457NA

Front Turn Signal

Years	Bulb Size
2013-2016	PY24WNA (With Halogen Capsule Headlamps)
2011-2012	3457NA (Main)
2010	3457NA (Main)
2010	12961 (Side rearview mirror)

Rear Turn Signal

Years	Bulb Size
2011-2012	PY21W
2010	12496

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament wedge bulb (T25), natural amber glass. 12V, 27W/7W.	3457NA
ANSI standard (US & Canada). Amber variant of ECE PY24W with PGU20-4 base. 12V, 24W.	PY24WNA
Philips part number. Miniature wedge bulb (T10) with W2.1x9.5d base. 12V, 5W.	12961
ECE standard (Europe & worldwide). Single-filament amber bulb with BAU15s bayonet base. 12V, 21W.	PY21W
Philips/Osram part number. Halogen bulb, specialty application. 12V.	12496

Other Locations

Additional Notes

The 3457NA is a dual-filament T25 wedge bulb rated at 12V with a 27W main filament and a 7W secondary filament. Its natural amber glass produces the required amber signal color without relying on a colored lens.
The "NA" suffix on both the 3457NA and PY24WNA designates compliance with ANSI standards for the United States and Canadian markets, distinguishing these variants from their non-NA counterparts used in other regions.
The PY24WNA uses a PGU20-4 base and is rated at 12V, 24W. It is the amber ANSI-market variant of the ECE PY24W and is specified for the Mercedes-Benz GL350 front turn signal positions on 2013-2016 model years equipped with halogen capsule headlamps.
The PY21W carries a BAU15s bayonet base and is rated at 12V, 21W. It follows ECE standards, which are used in Europe and most international markets, and it was specified for the GL350 rear turn signal on 2011-2012 model years.
The 3457NA and PY21W are not interchangeable. They differ in base type, filament count, wattage, and governing standard, meaning a direct substitution between the two would be incompatible.
The 12961 is a miniature T10 wedge bulb with a W2.1x9.5d base, rated at 12V and 5W. On the 2010 GL350, it is specified exclusively for the side rearview mirror turn signal position, a separate and distinct application from the main front turn signal.
The 2010 GL350 front turn signal position requires two different bulb sizes: the 3457NA for the main function and the 12961 for the side rearview mirror, indicating that these are physically separate lamp assemblies with different socket types.
The 12496 is a Philips/Osram part number for a 12V halogen bulb designated for a specialty application. It is specified for the 2010 GL350 rear turn signal, making it the only rear turn signal bulb in these specifications that differs from the PY21W used in 2011-2012.
The front inner turn signal position is listed only for 2010-2012, with the 3457NA specified across all three years. This position is absent from the 2013-2016 entries, which list only the front turn signal using the PY24WNA.
The PY24WNA and 3457NA are both ANSI-standard amber bulbs for the same front turn signal position, but they serve different model year ranges of the GL350 and use incompatible bases, making them non-interchangeable despite sharing the same general function.