The FC connector is a fiber-optic connector with a threaded body, which was designed for use in high-vibration environments. It is commonly used with both single-mode optical fiber and polarization-maintaining optical fiber. FC connectors are used in datacom, telecommunications, measurement equipment, and single-mode lasers. They are becoming less common, displaced by SC and LC connectors. The FC connector has been standardized in TIA fiber optic connector intermateability standard EIA/TIA-604-4.