Although the Amazon "does it fit?" function currently/erroneously states this O2 sensor fits an AUTOMATIC Mazda RX-8, part no. lookup on Bosch's website confirmed this is the OEM part for the rear/post-cat sensor on a 6-SPEED '04-'08 Mazda RX-8. Since my RX-8 has manual trans, I went ahead and bought this part to replace the original rear O2 sensor, which recently failed at 95 kmi, resulting in a check engine light. Before installing, I visually confirmed the new part is identical to the original part, and installation was a breeze - less than 10 minute job. The new sensor fixed my CEL, works perfectly.