TFC-110S20D3 or TFC-110S20D5 Bi-Directional Single Strand Fiber Media Converter transforms 10/100Base-TX UTP/STP media to 100Base-FX media and vice versa. The 10/100Base-TX Port Auto-negotiates between 10 and 100Mbps connection speed and supports Auto-MDIX. The 100Base-FX port supports single-mode SC type connection. These converters provide the ability to fiber optically connect networks together over distances of up to 20km.