I replaced the idler wheels on a 2004 WRX STi and a 2003 Forester with this part. Gates pulley and bearings are slightly better quality than factory. Apart from the rusty and stuck nuts/bolts that may be on the car, they are very easy to install. I had an annoying whine on my 2004 STi and was concerned that the crankshaft pulley might fail, but I decided to replace the cheapest part I could get my hands on first, which was the air conditioner and alternator idler pulley. This solved the problem. If your seat belt hardware is badly rusted, like it was on my Forester, be prepared to have to replace bolts, nuts and brackets as they can get stuck or break.