Today's ultra-light notebooks, mini, and all-in-one desktop computers now have tremendous processing power-power that many thought would only be possible in full-size workstation or large desktop computers. Smaller in size and more portable, they're very desirable. For pros in the creative fields, processing power alone is not enough. A prime example is the Mac Pro. Reviewers love its performance, but make a point of mentioning its lack of internal expansion capabilities compared to the old towers the model replaces. If you want to add more capabilities, think external - the Pro is loaded with Thunderbolt 2 and USB 3.0 ports, but it lacks the PCIe expansion slots necessary for you to install specialty high bandwidth NIC cards, or HBAs and RAID controller cards for high-performance storage. With the Echo Express SEL, Sonnet has created a solution that leverages the paradigm shift enabled by Thunderbolt technology, allowing PCIe expansion slots to be connected outside a computer. This very compact desktop Thunderbolt 2-to-PCIe card expansion chassis is ideal for connecting one professional 16 Gb or 8 Gb Fiber Channel, 10 Gigabit Ethernet, SAS/SATA host bus adapter or RAID controller PCIe card to any Mac with a Thunderbolt port.