Western Digital Elements Desktop. Hard drive capacity: 2500 GB. USB data transfer rates: 480 Mbit/s. Colour of product: Black. Input voltage: 100-240 V, Input frequency: 50/60 Hz. 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