This product is either discontinued or we cannot get that from suppliers.
Qnap Dual-port 40GBE LAN-40G2SF-MLX, 40 Gigabit Ethernet, FF Plug-in card, Network adapter, 40 Gigabit QSFP, Wired.
With the Dual-Port 40GbE SFP Network Expansion Card from QNAP users can take advantage of 40 Gigabit Ethernet speeds on QNAP NAS Systems. Included with the card are mounting.