Xbox 360 Hard Drive is a 20-gigabyte detachable hard drive that allows gamers to easily transport their saved games, downloadable content including music, downloaded trailers, levels demos and community created content from Xbox Live Marketplace.
Store - Store all of your games, music, downloaded trailers, levels, demos, and community-created content from the Xbox Live Marketplace.
Contents - Pre-loaded high-definition bonus content including Hexic HD, a popular puzzle game plus music tracks, skins, gamer pictures, videos, and more.
Expand - Build on your Xbox 360, since this drive is removable it can be replaced by a larger drive (when available) or used with the Xbox 360 Core system.
Backward Compatiblity - The Hard Drive also lets you play a selection of original Xbox games by download Backwards Compatibility patches.