. The industry-standard Cisco Small Form-Factor Pluggable (SFP) transceiver modules are hot-swappable input/output (I/O) devices that plug into 100BASE 1000BASE and 10GBASE ports (for SFP+) which connect the module port with the fiber-optic or copper network.. The 1000BASE-LX/LH SFP transceiver module for SMF compatible with the IEEE 802.3z 1000BASE-LX standard operates on standard singlemode fiber-optic link spans of up to 10 km and up to 550 m on any multimode fibers. When used over legacy multimode fiber type the transmitter should be coupled through a mode conditioning patch cable.. .