Replace the taillight or stop/tail bulb on your vintage scooter or motorcycle with this 6V 21/3CP Dual-Filament Taillight Bulb. This S25-style incandescent bulb uses a BAY15d offset bayonet base (15mm / 0.6" base diameter) and features two filaments — a brighter stop filament (21CP) and a dimmer tail filament (3CP) — making it the correct replacement for combined tail/brake light applications on 6-volt electrical systems.
Commonly used in vintage Vespa, Honda, and other classic scooters and motorcycles with 6-volt lighting systems. Use the AZScooterParts bulb chart to confirm fitment for your specific model.
Features
- Dual-filament: 21CP stop / 3CP tail in a single S25 bulb
- BAY15d offset bayonet base (15mm / 0.6") for secure, polarity-correct fitment
- 6-volt rated for vintage scooter and motorcycle electrical systems
- Clear glass envelope for use with colored lens housings
- Direct replacement for vintage Vespa, Honda, and other 6V tail/stop applications
Specifications
- Voltage: 6V
- Rating: 21/3CP (dual filament: 21CP stop / 3CP tail)
- Base Type: BAY15d offset bayonet (S25)
- Base Diameter: 15mm (0.6")
- Application: Tail / stop / combination rear lighting
- Filaments: 2 (dual-contact base)
California Prop 65 Warning: www.p65warnings.ca.gov
Model Fitment
Vintage Vespa, Honda, and other classic scooters and motorcycles with 6-volt electrical systems using BAY15d (S25) tail/stop bulbs. Use the AZScooterParts bulb chart to confirm fitment.
