Triumph Daytona 900 Super III Brake Bulb Size

The Triumph Daytona 900 Super III brake bulb utilizes a P21/5W size for replacement applications. The replacement chart covers vehicle production spanning 1994 to 1997.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
1994-1997	P21/5W

Bulb Specifications

Description	Bulb Size
ECE standard (Europe & worldwide). Dual-filament signalling bulb with BAY15d bayonet base. 12V, 21W/5W.	P21/5W

Other Locations

Additional Notes

The Triumph Daytona 900 Super III uses the P21/5W bulb for the brake light position across the 1994-1997 model years.
The P21/5W is an ECE-standard dual-filament bulb rated at 12V with two wattage outputs: 21W for the brake/stop function and 5W for the tail/position function.
The dual-filament design allows a single bulb to serve two lighting functions simultaneously, with each filament operating independently at its respective wattage.
The P21/5W uses a BAY15d bayonet base, which features two offset pins at different heights to prevent incorrect installation of the bulb in the socket.
The BAY15d base is not interchangeable with the single-filament BA15s or the symmetrical BAY15s bases, as the offset pin configuration is specific to dual-filament applications.
The ECE designation indicates the bulb conforms to United Nations Economic Commission for Europe regulations, a standard adopted across European and many worldwide markets.