This Thunderbolt 3 to 4 port PCIe USB (Universal Serial Bus) 3.1 hub connects your Thunderbolt 3 enabled computer to external USB (Universal Serial Bus) 3.1 (Gen 2) devices by combining a chassis with PCIe card. Connect your Thunderbolt 3 enabled computer to external USB (Universal Serial Bus) 3.1 (Gen 2) devices using this Thunderbolt 3 to PCIe USB (Universal Serial Bus) 3.1 adapter. Providing up to 10 Gbps throughput, the adapter offers four USB (Universal Serial Bus) 3.1 ports on two independent bus channels, an additional TB3 port, & a Display Port output. The adapter combines the Star Tech.com USB (Universal Serial Bus) 3.1 PCIe card (PEXUSB314A2V) & the TB3 chassis (TB31PCIEX16). With two host controller chipsets, shared across two ports instead of four, this 4-port Thunderbolt 3 to USB (Universal Serial Bus) 3.1 adapter dedicates up to 10 Gbps for each set of two USB (Universal Serial Bus) ports. It reduces performance bottlenecks & doubles your total available bandwidth to 20 Gbps. Thunderbolt 3 is the fastest connection available. By avoiding performance bottlenecks, you can accomplish more in the same amount of time. With 40 Gbps of throughput & support for other high-performance PCIe cards, you can swap the card in & out, to add the peripherals you need connected to a Thunderbolt 3 desktop or laptop computer. Requiring only a Phillips type screwdriver, this Thunderbolt 3 to PCIe USB (Universal Serial Bus) 3.1 adapter can be assembled & connected in minutes.