The fiber optic ST connector nails this with a simple but brilliant design. What Makes the ST Connector Tick? In fiber optics, everything hinges on a perfect connection. Your data is just pulses of light zipping through hair-thin glass strands. Even the slightest misalignment can throw that signal off course, causing data loss or a complete outage. 84ft) pigtails from Discount Low Voltage are great for fusion splicing inside of a fiber optic enclosure. 5mm ferrule made out of ceramic, stainless steel, or plastic, which helps keep the fiber cores aligned correctly so data can be sent accurately. They accommodate all industry-standard connector adapter types including the LC, ST® compatible, SC, SC duplex, FC and MT-RJ, as well as the keyed LC.