Backup battery (PRAM) board for 1GHz, 1.2GHz, 1.33GHz & 1.5GHz (Bluetooth 1.1) models of 15" Aluminium PowerBook G4. This board will not work in the Bluetooth 2 version of the 1.5GHz model. This board houses the rechargeable backup battery which stores settings such as the date & time. This board comes with the connector cable to connect it to the logic board.