FC type optical fiber adapter features: 1 good compatibility and high precision machine size high reliability and stability of ceramic and bronze catheter inserted core end face of PC, APC, UPC single-mode / multimode circular, square, square one split use: telecommunication network test equipment LAN fiber CATV different types of core inserted between switching performance index single mode : PC 0.3dB, UPC = 0.2dB, APC = 0.2dB multimode PC < 0.2dB insertion loss : < 0.2dB interchangeability: < 0.2dB > repeatability : 1000