The KTM 390 Duke uses a 9003 bulb size for both high beam and low beam headlight applications. The replacement chart covers vehicle production years spanning 2015 to 2018 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 listed across all headlight positions in the KTM 390 Duke specifications, covering both high beam and low beam functions for the 2015-2018 model years.
The 9003 is a dual-filament halogen bulb, meaning a single bulb contains two separate filaments within one glass envelope, one rated at 60W for high beam output and one at 55W for low beam output.
The 9003 operates on a 12V electrical system and uses a P43t base, which is a bayonet-style fitting with a 43mm collar width that physically locks the bulb into the housing.
The 9003 is defined under the ANSI standard, which is the classification system used in the United States and Canada, as noted in the specifications.
Because the KTM 390 Duke uses the same 9003 bulb for both the high beam and low beam headlight positions across 2015-2018, a single replacement bulb type serves both functions.
The 9003 bulb is functionally equivalent to the H4 bulb used under European ECE standards, though the two designations reflect different regional certification systems and may carry minor regulatory distinctions.
The P43t base is not interchangeable with other common motorcycle headlight bases such as the P14.5s or BA20d, so fitment is specific to housings designed for the P43t collar.