The Citroen DS21 Pallas uses an H5001 bulb size for high beam headlights and an H5006 bulb size for low beam headlights. The replacement chart covers vehicle production years from 1969 to 1972 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.
The Citroen DS21 Pallas uses two distinct sealed beam types across its headlight system: the H5001 for high beam and the H5006 for low beam, with both fitments remaining consistent across the 1969-1972 model years.
Both the H5001 and H5006 are sealed beam units built to ANSI standards, meaning they were designed for the North American market, specifically the United States and Canada.
A sealed beam unit integrates the filament, reflector, and lens into a single non-serviceable assembly. When a filament fails, the entire unit requires replacement rather than just an internal bulb.
The H5001 is a 4-inch square sealed beam unit operating at 12 volts, assigned exclusively to the high beam position on the DS21 Pallas.
The H5006 is a 5.75-inch round sealed beam unit, also rated at 12 volts, and serves the low beam position. Its larger round housing distinguishes it physically from the square H5001.
Because the H5001 and H5006 differ in both shape and size, the two units are not interchangeable with each other, and substituting one for the other is not possible without modification to the housing.