The Optical Fiber Connectors (Commonly we call Patch Cords) is a length of optical cable with connectors fixed on two ends to realize the optical path active connection. Pigtail is a length fiber cable with only one connector fixed on one end. If both sides of the connector or its end-face are different, we call it hybrid patch cord. According to the transmission medium, it divides Single Mode and Multi Mode; according to the connector structure type, it divides FC, SC, ST, MU, D4, E2000, LC etc.; according to the polished ceramic end-face, it divides PC,UPC and APC.