Maintain Fast Ethernet fiber connectivity without replacing stable infrastructure. StarTech’s SFP100BFXST is an uncoded 100BASE-FX SFP module designed for 100 Mbps Ethernet links over 1310 nm fiber. It fits environments where legacy switching, industrial gear, or access-layer equipment still depends on Fast Ethernet optics and where consistent interoperability matters more than chasing higher speeds. This module is a practical choice for extending or restoring fiber runs in networks that have standardized on 100BASE-FX. Its SFP form factor keeps deployment simple in supported ports, while the optical design is aimed at dependable transport for established infrastructure. For teams managing mixed-generation networks, it provides a clean way to preserve service on equipment that is still fully in use. Choose this module when the requirement is compatibility, not overprovisioning. It supports the kind of targeted replacement strategy that reduces downtime, avoids unnecessary hardware refreshes, and keeps older fiber segments operational with a purpose-built transceiver.