Fractal Design Venturi HP-14 PWM Black Case Fan FD-FAN-VENT-HP14-PWM-BK Featuring true FDB-bearings, providing silent operation coupled with a long lifespan Equipped with a counter-balancing magnet in the hub that reduces the axial tension on the bearing, further protecting the longevity of the bearing Dense, sturdy construction, made from high-grade glass fiber reinforced thermoplastic polymer with fan geometry that is optimized for a good balance between static pressure and maximum airflow, resulting in good performance in all usage scenarios Aerodynamically shaped thin stator struts (including wire strut), mimicking the design commonly found on airplane wings, delivering correct angles allowing for air to easily pass through reducing noise and unwanted turbulence Strategically placed notches near the fan hub on the trailing edge of the blades, further reducing and diffusing humming noise produced when the blades pass the stator struts 140mm fans come with an additional set of vibration-dampening corners are included that lends compatibility with 120mm fan mounts (105mm screw spacing). This enables the use of 140mm fans on many CPU coolers