High-performance work flows are possible by connecting a Thunderbolt equipped computer to a Thunderbolt expansion chassis containing PCIe cards such as video capture, media transcoding, audio processing, and fast data storage.Attach (3) full-length PCIe cards to your Thunderbolt equipped computer. ExpressBox 3T provides an 'outside-the-box' solution for using PCIe cards with Thunderbolt-equipped computers. High-performance work flows are possible by connecting a Thunderbolt equipped computer to a Thunderbolt expansion chassis containing PCIe cards such as video capture, media transcoding, audio processing, and fast data storage. And because Thunderbolt is also based on DisplayPort technology, you can daisy chain a high-resolution display with your Magma ExpressBox 3T.Interconnect Bandwidth 20 Gbps Bi-directionalHard Drive Support Optional built in drivebay for up to four (4) 2.5" SSD or SAS/SATA drives
(when using the drivebay, maximum card length is limited to 8.5")
http://magma.com/products/thunderbolt-expansion/expressbox-3t/