This product is either discontinued or we cannot get that from suppliers.
Qnap Quad M.2 2280 Pcie Ssd Expansion QM2-4P-284, Storage controller, FF M.2 2280/22110, Internal, Full-profile bracket, Low-profile bracket, Solid state drive.
QM2 series PCIe cards add support for M.2 SSDs to a QNAP NAS, allowing users to configure SSD caching, a caching pool, or an auto-tiering volume to improve overall NAS performance.