This is a gently used Sonnet Echo Express SEL PCIe expansion box with a Firewire 800/400 card to attach Firewire to Thunderbolt equipped computers. I was using this box to digitize mini DV tapes to a Mac but the internal PCIe card could be swapped to add new capabilities to laptops or desktops. Cosmetically in great shape and working flawlessly. It comes with AC adapter and a Thunderbolt 2 cable that the casing was scratched (thus the tape) but it is working perfectly and included as a bonus. This is way cheaper than buying Apple’s cable that can be damaged easily. This is a sturdy box.