OWC Accelsior 1A Apple Factory SSD to PCIe Adapter Card
Amazon.com: Sedna PCI Express (PCIe) SATA III (6G) SSD Adapter with 1 SATA III Port (with Built in Power Circuit, no Need SATA Power Connector, Best for Mac), SSD not Included :
StarTech.com M.2. PCI-e NVMe to U.2 (SFF-8639) Adapter - Not Compatible with SATA Drives or SAS Controllers - For M.2 PCIe NVMe SSDs - PCIe M.2 Drive to U.2 Host Adapter -
Full Speed M.2 NVMe SSD to PCIe Adapter with Heatsink
Cheap M.2 SSD to U.2 Adapter 2in1 M.2 NVMe and SATA-Bus NGFF SSD to PCI-e U.2 SFF-8639 Adapter PCIe M2 Converter for Desktop | Joom