The Iomega Silver Portable Hard drive is a pocket sized external hard drive that does not require an external power supply. It is ready to plug and play right out of the box. It comes in a variety of size options, including: 120GB, 160GB, 200GB, and 250GB. Like the other Iomega portable hard drives, this one is durable, enhanced by the Drop Shock technology implemented into the design. Included are disaster recovery and backup management software, a quick install guide, a supplemental power cord, HTML user manual, help files, and a one year warranty. Depending on the model it is compatible with USB 2.0/1.1 and 1394a FireWire400. The FireWire models have a transfer rate of 400 Mbits/s while the USB 2.0 have a transfer rate of 480 Mbits/s.