Professional 1-Port 6 Gb/s SATA Solution for Mac & PC Notebooks with ExpressCard Slot Why choose an eSATA Card? If you're planning to connect external storage to your computer, there's a good chance the enclosure will have two or more interfaces from which to choose, including USB, FireWire®, and eSATA. Your computer has USB ports, may have FireWire ports, and maybe even a Thunderbolt™ port, too. So if you can just plug into your computer's existing ports, why consider an eSATA card? Consider the facts that the 6 Gb/s eSATA interface offers superior performance to that of FireWire 800 and all USB interfaces, and Thunderbolt storage systems carry a price premium over eSATA storage systems. Sonnet's Tempo edge SATA Pro 6Gb ExpressCard/34 card is cost-effective solution for adding a single high-performance eSATA port to your computer through an adapter that practically disappears inside your computer.