Suzuki Motorcycle LT-A500 KingQuad AXi Tail Light Bulb Size

Additional Notes

• The Suzuki LT-A500 KingQuad AXi uses the P21/5W bulb type for its tail light across the 2009-2019 model years covered in these specifications.
• The P21/5W is a dual-filament bulb, meaning it carries two separate filaments within a single glass envelope. The 21W filament serves the braking or turn signal function, while the 5W filament handles the running light function.
• The P21/5W operates on a 12V electrical system, which is standard for this class of powersport vehicle.
• The base type on the P21/5W is a BAY15d bayonet fitting. The BAY15d designation indicates an offset pin configuration, where the two pins are positioned at different heights around the base. This offset prevents the bulb from being inserted in the wrong orientation, ensuring each filament connects to the correct circuit.
• The P21/5W is governed by ECE regulations, a standard recognized across Europe and numerous other markets worldwide. Bulbs carrying ECE approval are subject to defined output and performance requirements.
• Because the BAY15d base uses asymmetric pin placement, it is not interchangeable with the BAY15s base, which is a single-filament bayonet fitting with pins at equal heights. Substituting a single-filament BAY15s bulb into a BAY15d socket would result in incorrect circuit function.