Lexus RX450h Map Light Bulb Size

The Lexus RX450h map light requires bulb sizes 12961, DE3423, and 168 depending on the specific version. Data for the bulb sizes covers the range from 2010 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

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

Other Locations

Additional Notes

The Lexus RX450h map light specifications cover model years 2010 through 2016 and 2021, referencing three distinct bulb types across those years.
The 168 bulb is the most frequently specified type in these records, appearing across the 2010-2015 model years of the RX450h map light position.
The 168 is an ANSI-standard miniature wedge bulb in the T10 form factor, rated at 12V and 4.9W, with the wedge base making it a tool-free press-fit installation in compatible sockets.
The 2021 Lexus RX450h map light uses the 12961, a Philips-designated part rather than an ANSI-coded bulb, which means cross-referencing by ANSI number alone would not surface this fitment.
The 12961 shares the T10 form factor and W2.1x9.5d wedge base with the 168, but is rated at 5W versus the 168's 4.9W, making them functionally close though not officially interchangeable without manufacturer confirmation.
The 2016 model year uses the DE3423, a festoon-type bulb with a 41mm body and end-cap contacts, which represents a physically different construction from the wedge-base bulbs used in surrounding model years.
Because the DE3423 festoon and the 168 wedge use entirely different socket types, end-cap versus wedge, the two bulbs are not interchangeable despite both operating at 12V.
The DE3423 follows the ANSI standard applicable to the US and Canadian markets, as does the 168, while the 12961 follows Philips' own part numbering convention.