This product is either discontinued or we cannot get that from suppliers.
Synology Dual-Port, High-Speed E10G17-F2, 10GB, 2 x 10Gb Ethernet (RJ45), 2 x Enhanced Small Form-factor Pluggable (SFP+), PCIe 3.0 x8, Supported IEEE Standards 802.3ad, 802.3ae.
Synology Dual-Port, High-Speed 10GbE SFP+ ADD-in-Card NAS Accessories (E10G17-F2) Break through network bandwidth bottlenecks with the dual-port E10G17-F2 10GbE SFP+ add-in card