...Part Number: 911.631.101.00

The H-1 unit https://pbase.com/slidevalve911rsr/image/53604381 has all the virtues of the H-4 unit https://pbase.com/slidevalve911rsr/image/53328557 plus the advantage of two separate (high and low beam) reflectors and bulbs https://pbase.com/slidevalve911rsr/image/53604396 which can be independently aimed. For rallying, 100 watt bulbs can be fitted in place of the standard 55 watt units to produce an extremely bright light. Furthermore, it is possible to fit a relay to the headlight circuit permitting the burning of both bulbs simultaneously for super-bright performance.

FYI: The H-1 Dual-Bulb Headlamps are no longer available and difficult to obtain in "good-condition". The bulbs as well as the glass-lenses are still available. Lenses can be purchase for around $40 each. Below are some photos and sample recent sales...