It is mainly used to connect the terminals of two fibers. Pigtails are usually used inside terminal boxes, connecting the fibers in the optical cable to the. Fiber pigtails are simple in appearance, yet essential in function. They are the bridge between fiber optic cables in the field and the equipment or patch panels that manage them. By combining factory-installed connectors with spliced bare fiber, pigtails ensure that network installers can create. Fiber Optic Pigtails, also known as pigtailed fibers, consist of an optical fiber connector and a section of optical cable.