Roomy Chassis: 2U server case with 4 internal 3.5" HDD bays and 2 extra 2.5" device slots. Expandable & Micro-ATX Compatible: 4 PCI expansion slots and Micro-ATX compatibility gives you options for expansion. Quiet Cooling: 2 pre-installed 80mm PWM front cooling fans plus room for 1 additional 80mm fan 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 2 USB 3.0 port.