The Ducati 998 headlight bulb specifications include an H1 size for high beam and an H3 size for low beam applications. The replacement chart covers 2002 to 2004 production years with corresponding bulb size data.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Ducati 998 uses the H1 bulb for its high beam headlight across the 2002-2004 model years. The H1 is a single-filament halogen bulb with a P14.5s base, typically rated at 55 watts and designed for dedicated single-function lighting circuits.
The low beam headlight on the Ducati 998 uses the H3 bulb across the same 2002-2004 span. The H3 is also a single-filament halogen bulb, distinguished by its PK22s base and a compact, elongated envelope that differs structurally from the H1.
Because the H1 and H3 share a similar wattage rating but have entirely different base types, the two bulbs are not interchangeable. The P14.5s base of the H1 and the PK22s base of the H3 are physically incompatible with each other's sockets.
The H3 bulb connects to its socket via a wire lead attached to the base rather than through a plug-in connector, which is a notable handling difference compared to the H1 during bulb replacement.
Both the H1 and H3 are part of the ECE-regulated halogen bulb family, meaning they conform to internationally standardized output and safety requirements used across motorcycle and automotive lighting applications.