The 9003 bulb is the sole bulb type specified across all headlight positions for the Vespa Sprint, covering both high beam and low beam functions for the 2015-2018 model years.
The 9003 is a dual-filament halogen bulb, meaning a single bulb contains two separate filaments: one rated at 60W for high beam output and one rated at 55W for low beam output.
Because both the high beam and low beam positions share the same 9003 specification, a single bulb type serves both lighting functions rather than requiring separate bulbs for each.
The 9003 operates on a 12V electrical system, which is standard for most small-displacement motor vehicles and scooters.
The 9003 uses a P43t base, which is a bayonet-style mount with a 43mm flange. This base type determines physical fitment into the headlight housing and is not interchangeable with other base configurations.
The 9003 designation follows the ANSI standard used in the United States and Canada. It is functionally equivalent to the European H4 bulb, though the two designations originate from different regional standards bodies and packaging may differ.