Honda Motorcycle CTX700 front turn signal bulbs measure P21/5W in size while rear turn signal bulbs measure P21W, with both bulb sizes specified for the model. The replacement chart covers 2014 through 2018 production years and contains bulb size specifications for turn signal applications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Honda Motorcycle CTX700 uses two distinct bulb types across its turn signal system for the 2014-2018 model years: P21/5W at the front and P21W at the rear.
The P21/5W is a dual-filament bulb rated at 12V with a 21W primary filament and a 5W secondary filament, mounted on a BAY15d bayonet base.
The P21W is a single-filament bulb rated at 12V at 21W, mounted on a BA15s bayonet base.
Both bulb types conform to ECE standards, a regulatory framework recognized across Europe and numerous other markets worldwide.
The BAY15d base of the P21/5W and the BA15s base of the P21W are not interchangeable. The BAY15d features offset pins to accommodate its dual-filament design, while the BA15s uses a single-contact configuration.
Because the front turn signal position requires a dual-filament P21/5W, substituting a single-filament P21W in that position would be physically incompatible due to the differing base types.
The front turn signal specification remains P21/5W across all five model years covered, from 2014 through 2018.
The rear turn signal specification remains P21W across all five model years covered, from 2014 through 2018.