The Finisar FCLF-8521-3 is a copper SFP transceiver supporting 1000BASE-T over standard Cat5e or Cat6 cable, letting an SFP only switch port accept a normal copper Ethernet connection instead of fiber. This is useful when a switch has spare SFP slots but no free RJ45 ports, or when only fiber uplinks were originally planned for a rack. Antofity Concepts supplies copper SFP transceivers for organisations in Kenya needing to add copper ports to fiber only switch equipment.