SEV Marchal Amplilux Headlights
The lights were available as 7" assemblies and fit the standard mounting rings and housings used on the stock Porsche SB19 sealed beam housings used on the early U.S. delivered 911's. The dip and the full beam each use a single filament halogen bulb. The lower reflector uses a H3 bulb in its focal point to provide the high beam and the dip beam uses a H1 bulb.
The dual reflector and dual bubs engineered into each light assembly made them very expensive to manufacture but the Marchal lights were the best solution until dual filament halogen bubs were available in the mid 70s.
The high manufacturing cost and the dual filament halogen bubs eventually killed the production of the lights. Although the Marchal Amplilux lights have been around for a long time the lights still provide a very unique cut off low beam and a super intense, far reaching, pencil like, high beam that is not easily duplicated in a single light assembly.
The Marchal headlights require manual alignment because of the reflector design and because of the intense light beam created by the Marchal lights, it is very important to make sure they are correctly aimed to prevent blinding of oncoming drivers. This Daniel Stern Lighting website has an excellent article on how to do the manual alignment.
Note: Most information taken from the great article at "The Pantera Place" by Mike Daily