Bulb - Stop Tail 6V 21/3CP (17/5.3W) - BAY15D

The Link International 6V 21/3CP (17/5.3W) BAY15D is a dual-filament incandescent replacement bulb designed for stop/tail light applications on classic and vintage motorcycles with 6-volt electrical systems.

The BAY15D bayonet base features offset locating pins that prevent incorrect installation, ensuring the higher-wattage stop filament is connected to the correct circuit every time. A straightforward, like-for-like replacement for original-specification globes.

• 6V dual-filament incandescent bulb for combined stop and tail light duty
• 21CP (17W) high-intensity filament for the stop/brake circuit
• 3CP (5.3W) low-intensity filament for the running/tail light circuit
• BAY15D bayonet base with offset pins — prevents incorrect orientation on installation
• Direct replacement specification for vintage and classic motorcycles with 6-volt electrics
• SKU 45-481-30

• 1 x Stop/Tail Light Bulb 6V 21/3CP (17/5.3W) BAY15D

Switch the motorcycle's ignition off before removing or installing the bulb.
Handle the bulb by its metal base only — skin oils on the glass envelope can cause localised overheating and premature failure.
Align the offset BAY15D pins with the matching slots in the holder; the larger offset pin corresponds to the stop (high-wattage) filament circuit.
Press inward gently and rotate clockwise until the pins lock into the retaining slots; the bulb should be seated firmly with no movement.
After installation, confirm both the tail/running light and the stop/brake light function correctly before returning the lens to service.
Inspect the bulb holder contacts for corrosion or heat damage at each replacement; clean lightly with fine abrasive paper if needed.
Store spare bulbs in their original packaging in a cool, dry place away from direct sunlight to avoid UV degradation of the glass.
Do not operate a 6V bulb on a 12V system — incorrect voltage will cause immediate failure.