The 4WC unit has the same 4 - 92mm fans as the 4FN unit, but is pre-configured with the optional Cover Plate installed on the housing and the airflow of the fans is reversed. The unit, in its factory configuration, is designed to be used in applications that require all of the exhaust to be directed out the front of the unit. Depending upon how the unit is positioned, with the fans exposed on the top of the unit or the bottom, it can be used to pull air from below or above and direct it out the front of the unit. By reversing the factory airflow configuration, the unit can also be configured to pull air in from the front of the unit and direct it upwards or downwards.This is a very aggressive and versatile fullsized (same width as standard components)cooling unit. It circulates air away from components thus protecting equipment from heat accumulations and failures. This unit also allows for, and provides more advanced and unique features. The basic version features two top-quality 92mm Levitation fans that are mounted using special mounting hardware which eliminates noise caused by normal fan vibrations. The unit operates on DC voltage and, by adjusting the voltage, can be run silently or more aggressively depending on the application. This unit is ideal for directly cooling amplifiers and receivers installed in cabinetry or rack systems and can also ventilate entire racks and entertainment centers.