The apc rack fan tray is a low cost solution that aids in heat removal from a netshelter enclosure the system easily installs into the top of the enclosure and expels heat from the roof of the rack the acf504 fan tray promotes bottom to top airflow for a netshelter sx enclosure in zero u of space cools by exhausting heat out of the roof of the rack this product is designed for netshelter sx 750 mm