Mercedes-Benz GLS63 AMG Map Light Bulb Size

The Mercedes-Benz GLS63 AMG map light requires a bulb size of 12961 for the interior lighting system. Data for the specific component covers the range from 2017 to 2018.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
2017-2018	12961 (Rear)

Bulb Specifications

Description	Bulb Size
Philips part number. Miniature wedge bulb (T10) with W2.1x9.5d base. 12V, 5W.	12961

Other Locations

Additional Notes

The 12961 is a Philips part number designating a miniature wedge bulb in the T10 form factor, fitted with a W2.1x9.5d base. It operates at 12 volts and draws 5 watts.
The W2.1x9.5d base is a wedge-type connection, meaning the bulb is held in place by tension from the socket rather than by a bayonet or screw mechanism.
The Mercedes-Benz GLS63 AMG uses the 12961 bulb for the rear map light position across the 2017-2018 model years.
The T10 designation refers to the bulb's tubular envelope width, expressed in eighths of an inch, placing it among the smaller miniature bulbs used in automotive interior applications.
At 5 watts, the 12961 is a low-power bulb typical of courtesy and map light functions, where heat output and current draw are kept minimal.
The W2.1x9.5d base is a standardized wedge specification, and fitment depends on both the base type and the physical envelope size of the T10 form factor. Substitutions using a different base type would not be compatible with the GLS63 AMG's rear map light socket.