The SAT3520U2ER includes a large built-in 50mm fan that re-distributes the heat build-up generated as a result of typical drive operation which is especially important for larger volume storage 750GB 1TB hard drives and faster spinning drives i.e 7200 RPM as it can help optimize drive operability and in turn preserve stored data integrity.Primary InformationPC Compatibility :  Win; Linux Installed Modules Qty :  0 Modules Qty Supported :  2 PC Compatibility :  Mac OS Connections :  1 - USB B Female; 1 - eSATA Plug Expansion Bays Total Free  :  2 2 x internal - 3.5 x 1/3H Dimensions&MiscellaneousDepth :  7.80 Inch Width :  2.90 Inch Height :  3.00 Inch Storage ControllerRAID Level :  JBOD Supported Device :  Hard drive Storage Controller Type :  Serial ATA-300 PowerVoltage Required :  100-240V Power Device Type :  AC Adapters Service&SupportService & Support Type :  1 Year warranty Storage Hard DriveHard Drive Capacity :  1 TB Hard Drive Type :  External Hard Drive Interface Type :  Serial ATA-300 UNSPSC CodeUNSPSC Code :  43201601 

Model: SAT3520U2ER