Spacious Chassis: Huge 4U server case with 15 internal 3.5' HDD bays for massive storage. Exceptional Cooling: Upgraded Edition with Sudokoo 12cm PWM High-Airflow Fans for optimal airflow. Sudokoo SK120 PWM Fans - 500~3000 RPM±10% Expandable Design: 7 PCI slots and E-ATX compatibility for flexible expansion options. LED Indicators: Front panel LEDs for power, HDD, and LAN status for quick monitoring. Enhanced Utility: Includes 2 USB 3.0 ports and a built-in front panel lock for added security.