The ALCA H1 car bulb is a 12 V / 55 W halogen lamp with an H1 base — the standard fitment for low or high beam, fog lamps and auxiliary halogen spotlights on passenger cars. Supplied as a single bulb.
H1 base — check the code on your old bulb
The H1 base carries a single filament and one flat metal tab, so it seats in the reflector in only one position. The quickest way to confirm fitment is the H1 marking on the glass of the bulb you remove, or the car's handbook.
55 W at 12 V — the standard headlight rating
This rating matches the factory equipment of most passenger cars, so no wiring or relay changes are needed. Replacing both headlight bulbs at the same time keeps the light output even on either side.
Fitting without touching the glass
Handle the halogen bulb by its metal base only — finger grease burns onto the quartz glass at working temperature and shortens filament life. If the glass is touched, wipe it with alcohol and a dry cloth before fitting.