The DCE Rack System shall be configurable as a basic four-post open rack, a cabling and distribution enclosure or a complete server enclosure. DCE Racks shall include EIA-310E standard rack-mount rails. The core systems shall be factory-assembled, ready for the installation of customer-supplied electronic equipment. All DCE basic open rack, distribution and server enclosures shall be flexible and field-upgradeable with doors, panels, UPS, power distribution and fan options.