Drive Bay: 12 x hot-swappable SATA II, III/SAS 6G drive baysCooling Fan: 1 x 80mm rear fans, 3 x 40mm rear fansConnector:Three SFF-8088 connectors, each SFF-8088 port support 4 SAS or SATA drives;O.S. support:OS IndependentPower Supply Option: Standard ATX power supplyDimensions ( W x D x H ): 19" x 18.9" x 3.5" (483mm x 480mm x 88mm)Packing:Double boxesWeight (without hard drive): 11.3 kg/25 lb (NET) 12.7 kg/28 lb (GROSS) Environment Temperature:0/40 °C, 32/104 °F (Operating) -20/60 °C, -4/140 °F (Non-Operating) Relative Humidity: 5% to 95%,non-condensing