The FL-1F4E-SC20A/B is a compact, high-performance 10/100Mbps fiber media converter designed to convert Ethernet signals between copper and fiber interfaces. It comes with 4 x 100Mbps RJ45 ports and 1 x SC single-mode fiber port, supporting transmission distances of up to 20km. The converter is plug-and-play, requiring no configuration, making it easy to deploy in various networking scenarios. With its durable metal housing and strong resistance to electromagnetic interference, the FL-1F4E-SC20A/B is ideal for industrial automation, security monitoring, IP telephony, and other long-distance networking needs.