The Icy Dock MB561US-4S-1 eSATA/USB HDD Enclosure is a Direct-Attached Storage (DAS) device that will allow you to add 4 more HDD bays to your Windows Home Server and double your effective drive pool capacity. Assuming, of course, the WHS machine you have is a 4-bay appliance. MB561US-4S-1 still includes all the standard features. A single e-SATA port provides a direct, single connection and flexible options for advanced users. With a port multiplier e-SATA connection, you can either connect to a port multiplier JBOD adapter to access four drives via one e-SATA connection, or connect to a port multiplier RAID controller card. This is convenient for those who do video editing through Mac or PC and wants configurations of RAID 5 settings for increased storage capacities and blazing fast transfer speeds.
More info: MB561US-4S-1 4-Bay DAS Enclosure