Western Digital Black. Hard drive capacity: 320 GB, Hard drive interface: Serial ATA III, Hard drive speed: 7200 RPM. Power consumption (standby): 0.25 W, Power consumption (read): 2 W, Power consumption (write): 2 W. Width: 2.75" (69.8 mm), Height: 3.94" (100.2 mm), Depth: 0.276" (7 mm)