FOT4500 Optical Fiber Identifier is an important tool for optical maintenance, which is used for nondestructive fiber identification project. Meanwhile it also has Visual Fault Locator module with fault location function and power meter function..Using the macro bending technology on line for nondestructive testing, It can measure the signal direction and power and avoid mis-operation resulting in interrupted lines. ---Macro bending measurement. Macro bends are the use of fiber-optic bending leak out when the weak optical signal, optical signal to detect the direction and intensity. Does not damage optical fiber, without interrupting communications, and direct detection of 2.5mm bare fiber, 0.9mm and 2.5mm fiber casing tight jumper.