Is H4 Bulb High And Low-beam?
Is H4 Bulb High And Low-beam? The h4 headlight bulb is a dual filament bulb that does high and low beam in the same bulb. Are all H4 bulbs high and low beam? H4 Bulbs. H4 bulbs contain two filaments, giving them the option of being either high- or low-beam lights. The bulb has a