Looking for a high-quality, quiet fan to efficiently dissipate the heat inside your chassis? The Rosewill RNBD-131409 cooling fan is no doubt one of the best case fans in the market! The 140mm, nine-blade fan operates at 1200RPM ± 10%0RPM, delivering robust yet quiet cooling. The high-quality sleeve bearing ensures a long lifespan for hassle-free, long-term use. Includes LP4 adapter cables for compatibility. This cooling fan is sold as a pack of two. With nine blades and a 1200 RPM+/- 10%RPM rotation speed, this Rosewill case fan delivers a strong airflow up to 55.4CFM to effectively dissipate the heat generated inside the chassis.