Optical cords (patch cords) are designed to connect various segments of optical communication lines to each other, as well as to connect them to active network and test equipment. Patch cords provide high reliability of the connection and allow, if necessary, quickly re-switching. Optical connecting cords are a segment of optical cable terminated on both sides by identical connectors and are made of single-mode (yellow sheath) or multimode (orange sheath) fibers. Double cords are marked polarity connectors, through which you can determine the input and output of the light signal.