This firmware contains a digital signature. Once this firmware is installed on a Phaser 4600/4620 you will not be able to downgrade to previous unsigned versions of firmware.
Utilize this file for upgrading firmware over the network using CentreWare Internet Services (CWIS). This file contains machine firmware and release notes with installation instructions. Unzip the download before attempting to install the firmware.
See the release notes for details about this firmware.