Honda Motorcycle CB300F uses a 9003 bulb size for both high beam and low beam headlight applications. The replacement chart covers 2015 to 2018 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 Honda Motorcycle CB300F uses the 9003 bulb size for both its high beam and low beam headlight positions across the 2015-2018 model years.
The 9003 is an ANSI-standard bulb recognized in the United States and Canada, operating on a 12-volt electrical system with a dual-filament halogen design rated at 60 watts for high beam and 55 watts for low beam.
Because the CB300F (2015-2018) uses a single bulb type for both beam functions, the 9003's dual-filament construction is what allows one bulb to serve both lighting roles simultaneously.
The 9003 bulb uses a P43t base, which is a bayonet-style mount with a 43mm collar. This base type is specific to the 9003 and its international equivalent, the H4, and is not interchangeable with single-filament base types such as P14.5t or P22d.
The 9003 and H4 share the same physical form and electrical ratings, making them functionally equivalent in most fitment contexts. However, the 9003 designation follows ANSI standards while H4 follows ECE standards, and regional labeling on packaging may differ.