OWC 2.0TB Accelsior 1M2 NVMe PCIe SSD at MacSales.com
StarTech.com M.2 to U.2 Adapter - M.2 Drive to U.2 Adapter for M.2 PCIe SSD - U2M2E125 - Duplicators - CDW.com
Amazon.com: Sedna - PCI Express (PCIe) Dual 2.5 Inch SATA III (6G) SSD Adapter (Short Double Side SSD Version) (with Built in Power Circuit, no Need SATA Power Connector, Best for Mac),