Lexus RX350 Map Light Bulb Size

The Lexus RX350 map light uses bulb sizes 12961, DE3423, 168, and DE3175 depending on the specific version. Available data covers the range from 2007 to 2021.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
2021	12961
2016	DE3423
2010-2015	168
2007-2009	DE3175

Bulb Specifications

Description	Bulb Size
Philips part number. Miniature wedge bulb (T10) with W2.1x9.5d base. 12V, 5W.	12961
ANSI standard (US & Canada). Festoon bulb, 41mm length, end-cap contacts. 12V.	DE3423
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 4.9W.	168
ANSI standard (US & Canada). Festoon bulb, 31mm length, end-cap contacts. 12V.	DE3175

Other Locations

Additional Notes

The 168 bulb is the most frequently specified map light size across the Lexus RX350 model years provided, covering the 2010-2015 model years.
The 168 is an ANSI-standard miniature wedge bulb of the T10 type, operating at 12V with a rated power of 4.9W, and it follows a standardized designation recognized in both the United States and Canada.
The DE3175 festoon bulb is specified for the 2007-2009 Lexus RX350, measuring 31mm in length and making contact through end-cap terminals at each end rather than through a wedge base.
The 2016 RX350 uses the DE3423, a festoon bulb similar in construction to the DE3175 but with a longer 41mm body, making the two festoon types physically incompatible with each other despite sharing the same contact style.
The 2021 RX350 uses the 12961, a Philips-designated miniature wedge bulb of the T10 type with a W2.1x9.5d base, operating at 12V and 5W.
Although the 12961 and the 168 share the T10 bulb type classification, the 12961 carries a Philips-specific part number rather than an ANSI designation, and its wattage of 5W differs slightly from the 168 rated at 4.9W.
The wedge-base bulbs (168 and 12961) and the festoon bulbs (DE3175 and DE3423) represent two mechanically distinct base types, and fitment between these two categories is not interchangeable regardless of voltage compatibility.
The DE3423 and DE3175 are both 12V festoon bulbs but differ in body length, meaning a DE3423 would not seat correctly in a housing designed for the shorter DE3175, and vice versa.