Fiber optic converters are used in the fiber optic network to transform the signals sent from fiber glass to traditional UTP cables. They are typically used in Ethernet as physical layer networking equipment. Working distance of the fiber optic converters are different .for typical multimode fiber optic converters, their working distance max is about 2km, for single mode fiber media converters, their working distance can be 20km, 40km, 60km, 80km and up to 120km.