Roomy Chassis: This 3U server case has 6 internal 3.5’ HDD bays. Expandable & ATX Compatible: 4 PCI expansion slots and ATX compatibility gives you options for expansion. Quiet Cooling: 2 pre-installed 80mm front cooling fans provide excellent airflow and heat protection at reduced noise. Desired Features: Front panel LED indicators for power, HDD, and LAN status monitoring allow quick, easy visual assessment. Additional utility with 1 USB 3.0 and 1 USB 2.0 port.