INFINITI Q50 Stepwell Bulb Size

Additional Notes

• The Infiniti Q50 stepwell bulb specification calls for the 12961 across all listed model years, spanning 2014-2019 and 2021-2024.
• The 12961 is a Philips part number designating a miniature wedge bulb in the T10 form factor, which is one of the most widely used bulb types in automotive interior and courtesy lighting applications.
• The T10 bulb uses a W2.1x9.5d wedge base, a baseless design in which the glass envelope itself is held in place by spring tension within the socket rather than by a separate metal base.
• The 12961 operates at 12 volts and 5 watts, a rating typical of low-current interior lighting where heat output and power draw are kept minimal.
• Because the T10 wedge base is a standardized form factor, multiple manufacturers produce bulbs that physically fit the same socket, though the 12961 designation refers specifically to the Philips variant listed in these specifications.
• The W2.1x9.5d base designation is an IEC-standard code in which W2.1 refers to the base width in millimeters and 9.5d refers to the contact pin spacing, ensuring consistent fitment across compliant sockets.
• Stepwell bulbs illuminate the door sill area when a door is opened, and the 5W output of the 12961 is consistent with the low-intensity requirements of that application.
• The consistent use of a single bulb size across the full range of listed Q50 model years indicates that the stepwell socket specification did not change during that production period.