Synology E10G21-F2 Dual Port, 10 Gigabit Ethernet Card, Total Number of Ports: 2, Expansion Slot Type: SFP+, Form Factor: Plug-in Card, Network Technology: 10GBase-SR, Host Interface: PCI Express 3.0 x8, Media Type Supported: Optical Fiber. The Synology E10G21-F2 is a dual-port 10GbE SFP+ network interface card that lets you boost network bandwidth and performance. Handle more operations, users, and high-resolution videos.