What is U.2 SSD (formerly SFF-8639)? | Definition from TechTarget
U.2 NVMe SSD SFF8643 to SFF-8639 NVMe U.2 with Cable PCIe x16 Quad Port Adapter | eBay
U.2 PCIe 4.0 Adapter for 2.5 Inch U.2 SSD (SFF-8639) | GLOTRENDS
Icy Dock EZConvert MB705M2P-B Review M.2 to U.2 NVMe SSD Adapter
Amazon.com: MZHOU U.2 PCI-E ExpansionCard, SFF-8639 to SSD Adapter Card, PCI-E 3.0 X4 SATA Adapter- High Power Self-Powered The NVME Standard Protocol Supports WIN7/8/10/32/MAC/Linux : Electronics