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. You can. Fiber optic jumpers are used as jumpers for equipment to fiber optic cabling links. Let's take a closer look at the differences: First, jumpers, like Bridges in fiber optic communications, are equipped with. The main difference between these two cables is that the pigtail is terminated with a connector on one end and bare fiber on the other, while the jumper is terminated with both ends.