The Lexus RX300 tail light requires a 7443 bulb size for proper illumination and function. Data for the specified component covers the range from 1999 to 2003.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Lexus RX300 uses the 7443 bulb size across both the inner and outer tail light positions for the 1999-2003 model years.
The 7443 is a dual-filament wedge-type bulb, classified under the T20 form factor, operating at 12 volts with a wattage rating of 21W on the high filament and 5W on the low filament.
The dual-filament design of the 7443 allows a single bulb to serve two lighting functions, typically combining stop light and running light operation within one housing.
The 7443 conforms to ANSI standards, meaning it meets the standardized specifications recognized in both the United States and Canada.
Because both the inner and outer tail light positions on the RX300 share the same 7443 bulb size, the same replacement bulb is applicable to either location.
The wedge base of the 7443 is a baseless design where the glass envelope itself acts as the retention mechanism, fitting directly into a wedge-type socket without a separate metal base.
The 7443 is not interchangeable with the single-filament 7440 bulb, despite sharing the same T20 wedge form factor, because the 7440 lacks the second filament required for dual-function tail light operation.