The Moto Guzzi California Stone headlight bulb uses a 9003 size for both high and low beam functions. The replacement chart covers 2002 to 2005 production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 9003 bulb is the sole headlight bulb type specified for the Moto Guzzi California Stone across the 2002-2005 model years.
The 9003 is a dual-filament halogen bulb, meaning a single bulb contains two separate filaments to serve both high beam and low beam functions within one unit.
Because the 9003 handles both beam functions through its dual-filament design, the California Stone uses the same bulb size in both the high beam and low beam positions.
The 9003 operates on a 12-volt electrical system and draws 60 watts on the high beam filament and 55 watts on the low beam filament.
The 9003 uses a P43t base, which is a bayonet-style mount with a 43mm flange width, and this base type determines physical fitment into the headlight housing.
The 9003 is defined under ANSI standards and is recognized in the United States and Canada under that designation; it is functionally equivalent to the HB2 designation used in other markets.
The H4 bulb shares the same dual-filament configuration, P43t base, and 60W/55W rating as the 9003, making the two types cross-compatible in most applications, though the 9003 designation reflects the ANSI classification specific to North American markets.