Silicon Power 320GB Armor A50. Hard drive capacity: 320 GB, Hard drive interface: USB 2.0, Hard drive size: 63.5 mm (2.5 "). Data transfer rate: 480 Mbit/s, USB data transfer rates: 12, 480 Mbit/s. Colour of product: Gold. Mac operating systems supported: Mac OS X 10.4 Tiger, Mac OS X 10.5 Leopard, Mac OS X 10.6 Snow Leopard, Mac OS X 10.7 Lion. Weight: 200 g, Width: 133.8 mm, Depth: 78.3 mm