Flexibility in Fast Ethernet Connections This Fast Ethernet SFP transceiver enables one 100BASE-LX10 connection. This SFP can be used only in the 3Com Switch 5500-EI 28-Port FX, for its 100Mb connections. -100BASE-LX10 Fast Ethernet connection. - Supports link length of up to 10 kilometers using single-mode fiber. - Supports the IEEE 802.3ah Ethernet in First Mile over Point to Point Fiber (EFMF) standard. - Not for use in Gigabit SFP ports as found in many other switches.