Remove the existing bulb and compare the base, flange and contact layout with the cards above. Your owner’s manual will also list the fitting code and recommended wattage.

Both are H4-style dual-filament fittings, but the flange tab layout differs. Because of that, they don’t interchange—match the exact code stamped on your bulb or shown in the manual.

Often yes, if you choose the same fitting (e.g., P43T). Check reflector design, space behind the shell, and charging capacity. Some older bikes may need resistors or a regulator to prevent flicker.

Two filaments in one bulb: one for dipped beam and one for main beam. Common with P15D types and H4 families (P43T/PX43T).

Small flange or pin differences prevent correct seating (e.g., P15D-30 vs P15D-3). Compare caps side-by-side and check the code etched on the metal base.

British Pre-Focus. The flat flange with offset notches fixes orientation so the beam pattern stays aligned, widely used on classic British bikes.

No. BA20D is a bayonet cap with equal-height pins; P15D uses a pre-focus flange and push-fit. They’re different and not interchangeable.

Only if your wiring, switchgear and charging system can handle it. Excess wattage can overheat reflectors or stress the loom—always follow the bike’s spec.

Halogen typically 300–500 hours depending on vibration and usage; quality LEDs can last much longer. Replace bulbs that show darkening or output drop.

Headlight bulbs for all fittings above are available from Wemoto. Enter your bike details to filter compatible parts.