The Vespa PX 150 headlight bulb uses a 9003 size for both high beam and low beam applications. The replacement chart covers vehicle production years spanning 2005 to 2007.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 9003 is the sole bulb type listed across all headlight positions for the Vespa PX 150, covering model years 2005-2007.
The 9003 is a dual-filament halogen bulb, meaning a single unit contains separate filaments for both high and low beam output, which is why it serves both headlight functions in this application.
The 9003 operates on a 12-volt electrical system and draws 60 watts on high beam and 55 watts on low beam.
The 9003 uses a P43t base, a standardized bayonet-style fitting that determines physical socket compatibility.
The 9003 is defined under ANSI standards as used in the United States and Canada. It is electrically and functionally equivalent to the H4 bulb used under European standards, though the two designations reflect different regional classification systems and housing tolerances may vary between them.
Because the same 9003 bulb size is specified for both the high beam and low beam positions across all listed years, a single replacement bulb type covers all headlight functions on the Vespa PX 150 for the 2005-2007 period.