Also known as Fast Ethernet SFPs or 100BASE modules, these transceivers are far from obsolete. They offer a perfect blend of reliability, distance extension, and electrical isolation for environments where raw speed isn't the primary concern. 100BASE FX SFP remains a widely used solution for deploying 100Mbps fiber connectivity in industrial, enterprise, and legacy Fast Ethernet networks. While Gigabit and higher-speed optics dominate modern data centers, many control systems, surveillance networks, transportation infrastructure, and. The FS® 100BASE Small Form-Factor Pluggable (SFP) device (Figure 1) is a hot-swappable input/output device that plugs into Fast Ethernet ports, dual-rate Fast/Gigabit Ethernet ports, or Gigabit Ethernet ports of a FS switch or router, linking the port with the fiber cabling network. For a complete listing of hardware compatible with these modules, see the Extreme Optics. BIDI optical modules must be used in pairs. Although Belden makes every reasonable effort to ensure their accuracy at the time of this publication, information and specifications described here in are subject to error or omission and to change without notice, and the listing of such information and specifications does not ensure product. In the era of 5G, AI, and high-speed data centers, optical modules serve as the core bridge for converting electrical signals to optical signals (and vice versa), enabling fast, reliable data transmission across networks. Among various optical module form factors, SFP (Small Form-Factor Pluggable).