Samsung S2 Portable. Hard drive capacity: 640 GB, Hard drive interface: USB 3.0, Hard drive size: 63.5 mm (2.5 "). USB data transfer rates: 5000 Mbit/s. Colour of product: Grey. Width: 82 mm, Depth: 111 mm, Height: 17 mm. Operating temperature range (T-T): 5 - 40 °C