Move Fast Ethernet farther without redesigning the network. The Black Box LIC025A-R4 converts 10/100BASE-T copper to 100BASE-FX single-mode fiber using 1310 nm optics and SC connectivity, giving infrastructure teams a straightforward way to extend service across long distances. This model is well suited to remote buildings, distributed facilities, and backbone segments where copper reach is not enough and a switch replacement would add cost or complexity. By translating traffic onto single-mode fiber, it helps maintain signal quality over extended runs while keeping the copper side compatible with existing access equipment. The 40 km reach makes this converter a strong fit for long-haul enterprise links where reliability and distance matter more than feature density. It is the kind of purpose-built hardware that earns its place in the rack by solving one problem cleanly: getting Ethernet where copper cannot go, without forcing a broader infrastructure change.