Sonnet Echo Express III-D Thunderbolt 2-to-PCIe Expansion Chassis (Desktop) Compatible with host computers and other devices equipped with 10gbps thunderbolt technology Upgradeable-when available, upgrade to 40gbps thunderbolt 3 technology with a replacement thunderbolt interface card Three pcie slots-supports three full-length, full-height, single-width cards, or one double-width card plus one single-width card Remarkably quiet-large, temperature-controlled, variable-speed fans that automatically cool the cards