The Sega Saturn Backup Memory, otherwise called Back-Up RAM Cartridge in the US or Power Memory (パワーメモリー) in Japan, is an external storage cartridge used to save game progress and data as an alternative to using the system's internal memory. The cartridge provides over 16 times the amount of space; offering up to 512k of memory as opposed to the internal 32k.
The cartridge works similarly to the CD BackUp RAM Cart offered for the Sega Mega-CD.
Some games were distributed with stickers for the Backup Memory, including Policenauts and the North American release of Dragon Force.
There are also numerous Saturn third-party memory cartridges.