Pontiac Astre Dome Light Bulb Size

The Pontiac Astre dome light requires a unique 561 bulb size for the interior lighting system. Data for the specified lighting component covers the range from 1976 to 1977.

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
1976-1977	561

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, 44mm length, end-cap contacts. 12V, 12W.	561

Other Locations

Additional Notes

The 561 bulb is the sole dome light bulb size listed for the Pontiac Astre, covering the 1976-1977 model years.
The 561 is classified as a festoon-type bulb, meaning it is cylindrical in shape and makes electrical contact through metal caps at each end rather than through a base socket.
The 561 operates at 12 volts and draws 12 watts, which is consistent with standard automotive low-voltage electrical systems.
The 561 has a 44mm length, a measurement that governs fitment within the festoon holder, as the end caps must seat correctly against the spring contacts of the fixture.
The 561 carries ANSI standardization applicable in both the United States and Canada, meaning the designation refers to a consistent specification across both markets rather than a regional variant.