Amazon.com: PCIE to U.2 Adapter Card, PCIE X16 to 4 Port U.2 NVME SFF-8643/8639 Expansion Card, PCIE 4.0 U.2 Split Card with LED Indicator for Windows : Electronics
Any adapters for a x16 PCIe slot split in multiple smaller ones? | TrueNAS Community
PCIe splitter from x16 to 2x8 or 4x4, passive. - CPUs, Motherboards, and Memory - Linus Tech Tips
VOZFUN 1 to 4 PCIE Splitter, Pci-Express 16X Slots Riser Card, External USB 3.0 313048843813 | eBay
Dual M.2 PCIe NVMe Adapter Without PCIe Splitter Function (PCIe Bifurcation Motherboard is Required), Support M.2 PCIe 4.0/3.0 SSD Soft RAID Setup in Windows/Linux