The Xbox console has an 8 gigabyte (GB) hard disk that you can use for music, saved games, and more. Additionally, you can purchase the Xbox Memory Unit (MU) for the Xbox video game system that provides 8 megabytes (MB) or 502 blocks of additional storage space for use with compatible controllers. Gamers frequently use the memory unit to transfer saved games and Xbox Live accounts between different Xbox consoles. However, you cannot use the memory unit to store or transfer music files or downloadable content obtained from Xbox Live such as maps or roster updates. The memory unit is sold separately.