The Echo Express SEL Thunderbolt 3 to Low-Profile PCIe Card Expansion System from Sonnet provides a PCIe 3.0 x8 slot for Thunderbolt 3-equipped notebooks, SFF desktop systems, and other computers without a PCIe slot. The Echo Express SEL supports low-profile PCIe cards with a length of up to 6.6", such as audio interface, SAS or SATA HBA, 16Gb or 8Gb Fibre Channel, 10Gb Ethernet, or RAID controller PCIe cards, which operate over the Thunderbolt connection. There's also an integrated variable-speed fan for cooling your PCI card and the SE's internal components.
The Echo Express SEL Thunderbolt 3 Expansion System comes with two Thunderbolt 3 ports, letting you daisy chain up to six Thunderbolt devices to your computer. Each of the two Thunderbolt 3 ports transmits data at a rate of up to 40 Gbps and offers a USB Type-C design, so you can connect the included 1.6' Thunderbolt 3 cable on the first try. Moreover, a ThunderLok 3 Thunderbolt connector retainer clip is supplied to help ensure the cable stays connected to the chassis.