Why four stars? Because it could have been better. They could use better bearings, aside that it works as it should. Pumps lots of air into and out of my case and looks nice. To all the people who rate this fan very low because of its noisyness - 99,9% of case fans are making lots of noise when in contact with an obstacle(case's wall or whatever)! The given db specs are always measured without obstacles, hence the 19.5db the manufacturer gives it. Ive got 7 of these in my case, like I mentioned, they pump lots of air(like they should) but are not silent, still worth the few quid.