Dell Latitude 3520 original 256GB M.2 NVMe SSD (PCIe Gen3 x4, Class 35/40).
Form factor: M.2 (2230 or 2280 compatible with the laptop).
Typical speeds: up to \~2500–2700 MB/s read, \~1000–1200 MB/s write.
TLC flash. Pulled from working Latitude 3520 – tested and healthy.
Perfect upgrade or replacement for Latitude 3520 and many other Dell/HP/Lenovo laptops that take M.2 NVMe.
Contact for more details or test results.