H4 and 9003 bulbs have the same P43t base, which is a standardized base for many automotive/powersport bulbs. They share similar dimensions, making them fit into the same headlight housing without any modifications.
Both have a dual filament separating the high beam and low beam. This design is standardized for easy interchangeability between the two types.
The electrical connections are the same, which means that the wiring harness in most vehicles is compatible with both types of bulbs, making it convenient for car and motorcycle owners to switch from halogen to LED technology without rewiring their headlights.
LED Technology Upgrade
Eagle Lights LED H4's provide several advantages over traditional halogen bulbs, including improved brightness, longer lifespan, and lower power consumption. Our premium H4 LED bulbs come with a built in heatsink for optimal heat dispersion.