I bought these fans because they were the quietest (or one of the quietest) I could find. They were $12.99 each at Micro Center and well worth it. They're 120mm and put out about 71 CFM airflow at only 11db noise! They really are very quiet. I've got 4 of them in my case! Along with these, I have THIS CPU COOLER, and THIS CASE. They all combine to make my processor run at 40 degrees celcius even after 30 minutes of gaming!