The Triumph Rocket III high beam and low beam headlight bulbs both utilize a 9003 size. The replacement chart covers vehicle production spanning 2004 to 2010.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Triumph Rocket III uses the 9003 bulb for both high beam and low beam headlight functions across the 2004-2010 model years.
The 9003 is a dual-filament halogen bulb, meaning a single bulb unit contains two separate filaments to serve both beam functions rather than requiring two distinct bulbs.
The 9003 operates at 12 volts 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 fitment depends on this base type matching the headlight housing socket.
The 9003 designation follows the ANSI standard used in the United States and Canada, and it is electrically and physically equivalent to the European H4 bulb, though packaging and labeling may differ by market.
Because the same 9003 bulb specification applies to both the high beam and low beam positions on the Rocket III, only one bulb type is required to service the entire headlight assembly.