2-Pack, Ultra Sleek Vortex 140mm PWM Fan (with 120mm Mounting Pattern) The Ultra Sleek Vortex 14 is a 140mm desktop fan that is only 15 mm thick, making it easy to install in crowded cases and helps to free up space. The slim design makes it possible to fit into cramped areas and helps to improve airflow through the case be reducing case clutter. (Sold Individually, in 2-Packs, and 4-Packs on Amazon. Available in Black or White color.) Equipped with 4-Pin PWM for adjustable fan speeds from 300 to 1000 RPM, the Ultra Sleek Vortex 14 allows for almost absolute silence or high performance. Extremely quiet! Only 9 dBa at its lowest speed and 18 dBa at full speed! Specially engineered 17 blade fan design offers excellent airflow, pushing through 98 CFM of air. The Dual Ball Bearing offers long life and reliable operation. The Ultra Sleek Vortex 14 computer fan provides powerful static pressure of 0.9 mmH20 and is equally suited to perform as a radiator fan or case fan. The Prolimatech Static Booster may be installed to further increase static pressure (sold separately). IMPORTANT NOTE: This 140mm case fan is designed to be mounted on 120mm mounts. It will not fit 140mm mounts. For cases with two 120mm mounts directly next to each other, consider using the Ultra Sleek Vortex 12.