4U Rm 21.5IN 4 X Gputesla Case Type: 4U Rackmount Material: 1.2mm SGCC Sheet Metal, ABS-HB Plastic Material M/B Type: EEB (12 x 13 inch) Processor Support: Intel/AMD UP Quad; Intel/AMD DP Quad; AMD 4-Way Quad Expansion Slots: 8 Full-Height Cooling System: 1x 120x25 mm Front Fan; 2x 120x25 mm(Top Cover) Middle Fan; 2x 80x25 mm Rear Fan Front I/O Panel: 2x USB Ports