Triumph Rocket III License Plate Bulb Size

Additional Notes

• The 12961 is a Philips part number designating a miniature wedge bulb in the T10 form factor, operating at 12 volts and rated at 5 watts.
• The T10 designation refers to the bulb's tubular shape, with the number indicating a width of 10 thirty-seconds of an inch, a standard sizing convention used across miniature automotive lighting.
• The W2.1x9.5d base type is a wedge-style base, meaning the bulb is held in its socket by the tension of the base itself rather than by a bayonet or screw mechanism.
• The Triumph Rocket III uses the 12961 bulb for the license plate position across all listed model years from 2004-2010, indicating no fitment changes occurred during that production span.
• The 5-watt rating places this bulb in the low-output category typical of license plate and courtesy lighting, where illumination requirements are minimal compared to headlamp or signal circuits.
• T10 wedge bulbs share a widely used base standard, which means aftermarket and OEM-equivalent replacements from manufacturers other than Philips may carry different part numbers while remaining physically and electrically compatible with the W2.1x9.5d socket.