The FirmTek ThunderTek/PX PCIe Expansion Chassis is designed to connect a PCIe 2.0 card to 2011 or later MacBook Pro, MacBook Air, iMac, Mac mini, 2013 Mac Pro or other Thunderbolt™ equipped computers. The small, lightweight ThunderTek/PX, is perfect for supporting a single half-length PCIe card. Its silver brushed aluminum body provides durability and active heat dissipation, along with a whisper quiet fan. Optional eSATA Bundle - FirmTek offers a special eSATA bundle that turns the chassis into a powerful Thunderbolt to eSATA adapter. Known as the ThunderTek/PX-Q6G, this bundle includes a high performance 4-port, eSATA 6G SeriTek/Q6G card and the ThunderTek/PX expansion chassis.