Fiber Coloane diagnostics to help you quickly find the point of failure, regardless of the motherboard transceiver problems, or connected to the light problems. MOST Optical Fiber Loop can delete or add individual automotive equipment which does not affect the car fiber-optic network.Bluetooth phone module was often damaged when opening stereo, the sound went intermittently, sometimes no with no sound, the fiber head of the phone module can be pulled out, connected to the fiber loop, deactivate the Bluetooth phone function, audio immediately returns to normal.Specification:-Material: Plastic-Core diameter: Φ1-Attenuation:＞180dB/km-Operating temperature: -55℃-+85℃-Suitable for cars such as BMW,VW,Mercedes-benz,Audi,Porsche