Designed for select Synology NAS servers, the  E10G18-T1 10GbE PCIe Expansion Card  from  Synology  has a single RJ45 port that supports 802.3an 10 Gb/s Ethernet, 802.3bz 2.5 and 5 Gb/s Ethernet, 802.3ab Gigabit Ethernet (1 Gb/s), 802.3u Fast Ethernet (100 Mb/s), and 802.3x Flow Control.

It has a low-profile/full-height bracket, a PCIe 3.0 x4 interface, operates in full duplex mode, and can auto-negotiate between 10 Gb/s, 5 Gb/s, 2.5 Gb/s, 1 Gb/s, and 100 Mb/s speeds.