Cisco offers a wide variety of connectivity, expansion and upgrade modules to accommodate the range of application needs in customer networks. The network modules assure customers that they can choose a connectivity solution that fits their requirements. As modular components, they are easily and inexpensively field-upgradeable as customer requirements change.The Processor Switching Module PXM45 card set consists of the PXM45 front card, the PXM User Interface back card (PXM-UI-S3) and the PXM Hard Drive back card (PXM-HD).