100Base-FX Multi Mode to Single Mode Fiber Converter (15KM). TRENDnet's TFC-100 series Fiber Media Converter transforms 100Base-TX UTP/STP media to 100Base-FX media and vice versa. The 100Base-TX port auto-negotiates half-/full-duplex connection and it has a slide-switch for selecting MDI-X / MDI-II media type. This converter will give your Switch/Hub the ability to interface with fiber connections over a distance up to 75 km. With the optional 16-slot EIA-19" rack-mount chassis