Upgrading an older iMac's PCIe SSD: Third-party solutions that save you beaucoup bucks | Macworld
MAC SSD Solid State Hard Drive PCIE Gen 3.0X4 Nvme 1.3 3D NAND TLC Three-Layer,Support TRIM,T.M.A.R.T,Read Up to 2,000MB/s Compatible with Apple MacBook Air,MacBook Pro,iMac,Mac Pro,Mac Mini 512 GB - Newegg.com
ADAPTER FOR NON APPLE PCIE M.2 SSD FOR IMAC MACBOOK AND MAC MINI | AvenueMac
KINGDATA High-Speed PCIe NVMe SSD 256GB Upgrade for Your MacBook, Boost Performance and Storage Capacity Internal Solid State Drive for MacBook Air/Pro/iMac - Walmart.com
NevMXM NVMe Adapter for A1311/A1312 iMac from iBoffRCC on Tindie