StarTech.com Thunderbolt 3 to FireWire Adapter - External PCI Enclosure - PCIe Card plus TB3 Chassis - The Thunderbolt 3 to 1394 FireWire adapter connects your FireWire peripherals to your Thunderbolt 3
Startech Thunderbolt 3 PCI-E x16 Adapter Black | Techinn
Amazon.com: HP 3UU05AA Dual Port Add-in-Card - Thunderbolt Adapter - PCIe - Thunderbolt 3 X 2 : Electronics
Node Duo - Thunderbolt 3 PCIe expansion chassis for 2 cards | AKiTiO
Sonnet Echo III - Thunderbolt 3 to PCIe Expansion Enclosure
Amazon.com: ASUS ThunderboltEX 3-TR Expansion Card for Z490 (Intel 10th Gen CPUs)motherboard (PCIe 3.0 x4 interface, 2 x Thunderbolt™ 3 USB Type-C® ports with 100w USB quick charge, 2 x mini DisplayPort