I bought this in place of a BMW branded product. Fits perfectly. Ease of installation. I can confirm this part will fit and work on E60 2008 528i and N52 engines. I'm a hobby mechanic and I repair my BMW myself. Replacing the tensioner, idler and belt took about 1 hour. You can't thread the old tensioner through the top of the block, so you'll have to pull it out from underneath. The new tensioner works the same way. Very easy to fix and definitely a job that an inexperienced home mechanic could do alone. Will be using ContiTech to replace all accessory belts on my BMW in the future. Great part and great quality.