The 1000BASE-ZX 1550nm DFB+APD Small Form-factor Pluggable (SFP) Gigabit Ethernet Transceiver, 120KM reach, DDM functionality, 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# GLC-EZX-SM)