The Aprilia RS4 125 headlight bulb size specifications indicate that both high beam and low beam applications utilize an H11 bulb size. The replacement chart covers vehicle production years spanning 2011 to 2016.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Aprilia RS4 125 uses the H11 bulb type for both high beam and low beam headlights across the 2011-2016 model years.
The H11 is a single-filament halogen bulb, meaning it contains one tungsten filament and is not designed to serve dual lighting functions within a single unit.
H11 bulbs operate at 12 volts and 55 watts, which are standard ratings for halogen headlight applications in small-displacement motorcycles.
The H11 carries the PGJ19-2 base designation, a connector and mounting standard that determines physical fitment into the headlight housing.
The H11 is produced to ECE (Economic Commission for Europe) standards, giving it regulatory acceptance across Europe and numerous other markets worldwide, and it also holds approval for use in the United States.
Because both the high beam and low beam positions on the RS4 125 share the same H11 specification, a single bulb type covers both headlight functions on this model.