Review on Enhance Desktop Performance with NVMe PCIe Adapter - M.2 SSD to PCIe X4/X8/X16 Conversion Card: Compatible with Samsung 960Evo, SM961, SM951, PM961, and More by Alexander Scharon

It's very primitive but works great. It's basically just a small piece of PCB with an m2 slot that plugs into a PCI x4 slot or larger slot. It doesn't really extend to the edge of the case to fit properly in my system, nor does it seem particularly secure in the x16 slot, so I wouldn't recommend using it for a high-performance nvme drive with a large to use heavy heatsink. to that, but these are usually expensive PCIe 4.0 drives and you obviously need a PCIe 4.0 slot for them anyway. If you're just looking to add an NVME m2 slot to a system that doesn't have one, or ditch an old, slower drive from one of your prized PCIe 4 slots but still want to use it, this should suit your needs and improve performance . for less money compared to the outer case.