Only one end of the optical fiber pigtail has a connector, and the other end is a broken end of an optical cable core, which is used for the connection between the optical cable terminal box and the equipment. One end of the pigtail is fused with the optical fiber connector, and the other end passes through (LC, SC, FC, ST) connectors are connected to fiber optic transceivers or optical modules to form an optical data transmission path. The main cable of the bundled fiber pigtail is a round cable. By default, OPTICO uses black heat shrinkable tubes as branch nodes, which effectively saves costs and ensures Good mechanical and optical properties.