Direct fit for the downstream oxygen sensor on my 1997 Rav4, it goes in right past the catalytic converter that's in the exhaust manifold. Same manufacturer as OE without paying dealer price. I paired this with the Denso 234-2058 upstream oxygen sensor to replace both of my sensors at the same time which I'm pretty sure were original with over 200k miles and were contaminated pretty good. I saved 2/3 the money I would've had I bought these at a Toyota dealer.The new sensors, compared to the original, smoothed out my throttle response and acceleration. Good tune-up item if you have never replaced these, as they are recommended replacement every 50-60k miles. TOP TIP: PB Blaster/AeroKroil sprayed on the threads a few days prior help making removal easier.