Honda Motorcycle CMX300 Rebel 300 Turn Signal Bulb Size
Honda Motorcycle CMX300 Rebel 300 front turn signal bulbs use P21/5W size while rear turn signal bulbs use P21W size. The replacement chart covers 2017 to 2019 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 CMX300 Rebel 300 uses two distinct bulb types across its turn signal positions: the P21/5W at the front and the P21W at the rear, across the 2017-2019 model years.
Both bulb types conform to the ECE standard, which is a lighting regulation recognized in Europe and internationally.
The P21/5W is a dual-filament bulb, meaning it carries two separate filaments within a single housing, rated at 12V with a 21W primary filament and a 5W secondary filament.
The P21W is a single-filament bulb rated at 12V and 21W, dedicated solely to turn signal operation at the rear.
The P21/5W uses a BAY15d bayonet base. This base type features offset pins, which physically prevents incorrect installation of a single-filament bulb in a dual-filament socket.
The P21W uses a BA15s bayonet base, a single-contact fitting that is not interchangeable with the BAY15d base used at the front.
Because the front and rear sockets use different base types, BAY15d and BA15s respectively, a P21W cannot be substituted into the front turn signal position of the CMX300 Rebel 300, nor can a P21/5W fit the rear.