WD  My Passport Essential 400 GB USB 2.0 Portable External Hard Drive (Intense Blue) Box Contents - My Passport Essential 400GB Portable USB Hard Drive, USB 2.0 cable, Quick Install guide 400GB Hard Drive Capacity Installation is a snap because you don't really install this drive; you just plug it in and it's ready to use. There is no CD to install; the included software loads from the drive the first time you plug it in Powered by the USB bus. No separate power supply is needed This ultra-portable drive fits easily in your pocket or purse, weighs only a few ounces, and holds tons of valuable data