SilenX EFX-12-15T Effizio 120x25mm &lt;15dBA &lt;74CFM Thermistor Computer Case Fan The combination of an advanced swept-forward fan blade design, reduced motor size and conical hub allows for more air to be pushed per revolution, resulting in less noise and greater airflow. Competing fans have a flat cylindrical hub and improper fan blade geometry which creates a large dead-spot in degards to air movement and impedes airflow. Offers long-life and reduced noise as it dampens vibration from the motor itself and from external sources. It's the very reason all PC hard-drive makers have also made the switch to fluid dynamic bearings from other bearing types. Japanese bearings from a world leader with years of expertise in bearing technology for long life and durability. Silicone-composite fan mounts and a stronger formulation of polycarbonate was utilized to minimize flex and reduce vibration resonance with your chassis. These features combined with the vibration dampening aspects of fluid dynamic bearings and optimized fan blades ensure the little details were never left out to make the best fan possible.