Amazon.com: Cablecc PCI-Express PCIE PCI-E X1 X4 X8 X16 to PCI Bus Riser Card Adapter Converter with Bracket for Windows : Electronics
PCIEX16D03 | PCIe x16 to two PCIe x8 Slots Expansion Board | GPU Docking | GPUs Docking
M.2 PCIe NVMe SSD to PCI-E Express 3.0 X4 X8 X16 Adapter Card Full Speed 2280 mm | eBay
Flexible PCI Express X8 to X16 Riser Card [ST8026] - $8.99 : Sintech Eshop!, The World of PC Adapter Card
Which GPU gets bottlenecked by PCI-E 3.0 x8 vs x16 ? Is any of them even bottlenecked ? : r/buildapc
Amazon.com: GLOTRENDS M.2 PCIe X1 Adapter with M.2 Screw for M.2 PCIe 4.0/3.0 SSD (NVMe/AHCI Key M), PCIe X1/X4/X8/X16 Lane Installation, but Only PCIe X1 Bandwidth (PA09-X1) : Electronics
Amazon.com: BEYIMEI PCI-E Card 4X to USB 3.1 Gen 2 (10 Gbps) Type A+Type C Expansion Card Asmedia Chipset for Windows 7/8/10 Compatible Slot: PCIe x4, PCIe x8, PCIe x16 (Type A+Type