StarTech.com TB31PCIEX16 Thunderbolt 3 PCIe Expansion Chassis - Thunderbolt 3 to 16 x PCIe - Aluminum - PCIe SSD - External PCIe Enclosure - PCIe Slot

Additional Info

Add an external PCI Express 3.0 x16 slot and a 4K DisplayPort connection to your Thunderbolt 3 MacBook or laptop
Add PCIe cards such as an SSD / Ethernet or Fiber / Video Capture / USB / FireWire or eSata cards to your Thunderbolt 3 laptop
Add an additional PCIe card to a Thunderbolt 3 computer
Increased productivity with Thunderbolt 3 and up to 40Gbps bandwidth
Thunderbolt 3 to PCIe / Thunderbolt 3 PCIe Enclosure / Thunderbolt 3 Expansion Chassis / Thunderbolt 3 PCIe Box

Escrow option available