The TP-Link TL-FC111B-20 is a high-performance 10/100 Mbps WDM media converter designed to bridge copper and fiber networks efficiently. It complies with IEEE 802.3, 802.3i, and 802.3u standards, offering one 10/100 Mbps RJ-45 port and one 100 Mbps SC fiber port. Utilizing advanced WDM (Wavelength Division Multiplexing) technology, it transmits and receives data over a *single* single-mode fiber (9/125 µm), dramatically reducing fiber cabling costs and complexity.

Key features include the ability to extend fiber connections up to 20 kilometers and operate with wavelengths of 1310 nm for transmission and 1550 nm for reception. This model pairs perfectly with the TL-FC111A-20, which uses the complementary wavelengths, ensuring seamless duplex communication.

The unit supports auto-negotiation for half/full duplex modes and auto MDI/MDIX on the copper port, simplifying setup. Its compact, sturdy metal casing measuring 94.5 × 73 × 27 mm ensures reliable operation in various environments with a wide operating temperature range of 0°C to 50°C and storage conditions from -40°C to 70°C.

Ideal for applications such as park security monitoring, wireless networking, and other commercial scenarios requiring long-distance fiber links, the TL-FC111B-20 can be used as a standalone device or mounted on TP-Link's TL-FC1420 rack for consolidated deployment. LEDs indicate power and link/activity status, enhancing ease of use.

In the box: media converter unit, power adapter (5 V / 0.6 A), and installation guide.

For detailed support resources, refer to TP-Link’s official website.