PC Fan Be quiet! Pure Wings 2 140mm:The unique technology has a fan Pure Wings 2 optimized airflow. Effectively blows cool air into the cabinet and achieves an extremely silent operation it will not interfere.Pure Wings 2 delivers casing airflow and improves the cooling efficiency of each component. Thanks to the specially designed blades and the needle bearing, the fan is quiet and does not disturb you when working or playing games. With integraged PWM technology , the fan is compatible with a variety of boards that support intelligent speed change. Even less noise is made because the fan automatically adjusts to the computers performance. The fan can be completely at rest or at the maximum when needed.Key featuresOptimsed, silent airflowUnique blade designLife up to 80,000 hoursAutomatic speed control (PWM)