The 1000BASE-LX 1310nm Small Form-factor Pluggable (SFP) Gigabit Ethernet Transceiver 550m with DDM function is a hot-swappable input/output device that plugs into a Gigabit Ethernet port or slot, linking the port with the network. The SFP provides full-duplex Gigabit Ethernet connectivity over existing copper network infrastructure. (Cisco part# SFP-GE-L)