Samsung Mz-flv2560 256gb M.2 2280 NVMe SSD for sale online | eBay
The 128GB Surface Pro 4 models use perhaps the worst NVMe based SSD in production (link is closest model on Samsung's site, but specs line up with benchmarks) : r/Surface
M.2 (NGFF) SSD to PCIe 3.0 X16 Card for Samsung 960 970 EVO
Samsung MZFLV256HCHP-000MV - 256GB M.2 PCIe NVMe 2280 MLC 3D-Nand SSD Solid State - CPU Medics