Abstract: The filaments for high beam and low beam are in respectively parallel planes, and the axis of the low beam filament forms an angle .alpha. which is less than 90.degree. with the lamp axis, or seal beam headlamp axis, respectively, the angle being suitably between about 30.degree. and 60.degree., and preferably about 45.degree., upon projection of the lamp axis, in parallel, in the plane which includes the axis of the filament. The inclination of the low beam filament facilitates adjustment of the headlamp to provide, reliably, glare-free road illumination in accordance with SAE standards.