This product is either discontinued or we cannot get that from suppliers.
Qnap Quad M.2 2280 Sata Ssd Expansion QM2-4S-240, M.2 to PCI Express Adapter, Connector 4 x M.2 2280 SATA SSD slots, PCIe and Lanes PCIe Gen2 x 4.
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.