RIITOP PCI-e Nvme M.2 Adapter NVMe or AHCI M Key SSD to PCIe 3.0 x 4 C
NVMe M.2 SSD to PCIe X16/X8/X4 Card - Sabrent
The M.2 interface
M.2 To Usb Adapter B Key M.2 Ssd Adapter Usb 3.0 (no Cable Needed) Usb To 2280 M2 Ssd Drive Adapter Ngff Converter Ssd Reader - Pc Hardware Cables & Adapters - AliExpress
M.2 Interface, Key and Socket explained
For Raspberry Pi 4, X862 V2.0 M.2 NGFF SATA 2280 SSD Storage Expansion Board – Geekworm