An electrical pigtail is a short piece of wire used to connect an electrical device, such as a switch or receptacle, to the main circuit conductors within a junction box. This technique ensures the device is. The Fiber Optic Patch Cord, also referred to as a fiber optic patch cable or fiber jumper, is a specialized cable designed for transmitting data signals using light waves in fiber optic communication systems. Pigtails serve. In fiber optic communication systems, fiber patch cords and fiber pigtails are two common fiber optic components.