The IBM DS4000 EXP810 comes in a 19-inch rack mount package. The EXP810 Storage Expansion Unit provides a 16-bay disk enclosure that attaches to the DS4000. With a maximum of 4.8TB of physical capacity per expansion unit using 16 300GB disk drives, the EXP810 allows 2Gbps Fibre Channel Enhanced Disk Drive Modules. The EXP810 also allows 4Gbps Fibre Channel E-DDM or 4Gbps Serial ATA E-DDM. Frontier offers used and refurbished DS4000 EXP810s. Call today or request a quote. 866-226-6344