500GB Canvio Slim II Portable External Hard Drive (PC Model Black); Specification: Capacity: 500GB Interfaces: USB 3.0 (backwards compatible with USB 2.0) Interface Transfer Rate: Up to 5 Gb/s (USB 3.0) Up to 480 Mb/s (USB 2.0) Speed: 5400 RPM Average Seek Time: 12 ms Cache Buffer: 8 MB