Volkswagen Squareback Dome Light Bulb Size

The Volkswagen Squareback dome light requires a 6411 bulb size for proper installation and function within the interior lighting housing. Data for the specific component covers the period from 1969 to 1973.

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
1969-1973	6411

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, 36mm length, SV8.5 base. 12V, 5W.	6411

Other Locations

Additional Notes

The Volkswagen Squareback uses the 6411 bulb for its dome light across the 1969-1973 model years.
The 6411 is a festoon-style bulb, meaning it is cylindrical in shape and mounts by pressing its end caps into spring clips rather than inserting into a socket.
The 6411 carries an ANSI designation, indicating it meets a standardized specification recognized in both the United States and Canada.
The bulb operates at 12 volts and draws 5 watts, which is consistent with low-power interior lighting applications in 12-volt automotive electrical systems.
The 6411 has a length of 36mm, a specification that is critical for fitment, as festoon bulbs must physically span the distance between the two mounting clips in the fixture.
The SV8.5 base designation refers to the metal end cap width of 8.5mm, which must correspond to the clip width of the Squareback's dome light housing for proper contact and retention.
Festoon bulbs of the same voltage and wattage but different lengths or base widths are not interchangeable, as a mismatch in either the 36mm length or the SV8.5 base will result in poor fitment or no electrical contact.