Designed to integrate the user's custom requirements into a CompactPCI system, the Compact-I sub-rack is well-suited for use in medium- to high-volume applications such as are found in the telecomm, datacomm and computer telephony industries. Versions of the system include an all-sheet steel design that can be customized for high-volume applications with limited cPCI features and a sheet metal/extrusion design that can be customized for applications that require all cPCI features at a moderate cost. Other features include: unique inner cPCI cage; a comprehensive choice of hot-swap, modular cPCI backplanes; several climate control options; a variety of power supply versions; slide-out chassis; and EMI/RFI containment.