The Node 304 accommodates up to six hard drives. Unused mounting brackets can be removed in favor of long graphic cards, additional airflow or more space for organizing cables. Additionally, it is equipped with three hydraulic bearing fans, easy-to-clean air filters in all intakes and two front Usb 3.0 ports.3x Silent fansThree Silent Series R2 hydraulic bearing fans included.Dust-free filtersFiltered air intakes ensure a dust-free environment for internal components.usb 3.0 ConnectorsUSB 3.0 for fast file transfers..