The Triumph Rocket III Classic uses 9003 bulb size for both high beam and low beam headlight applications. The replacement chart covers vehicle production spanning 2006 to 2009 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 bulb type specified across all headlight positions for the Triumph Rocket III Classic, covering the 2006-2009 model years for both high beam and low beam functions.
The 9003 is a dual-filament halogen bulb, meaning a single bulb contains two separate filaments: one rated at 60 watts for high beam output and one rated at 55 watts for low beam output.
Because both the high beam and low beam positions share the same 9003 specification on the Triumph Rocket III Classic, a single bulb type serves both lighting functions within the same housing.
The 9003 operates on a 12-volt electrical system, which is standard for motorcycle and automotive applications of this type.
The 9003 uses a P43t base, a bayonet-style mount with a 43mm collar, which physically determines fitment and is not interchangeable with bulbs carrying different base types even if wattage ratings are similar.
The 9003 is defined under ANSI standards and is the designation used in the United States and Canada. It is electrically and physically equivalent to the H4 bulb used under European ECE standards, though regulatory and labeling distinctions exist between the two designations.