Usage:If you meet the faults of audio CD and navigation , audio CD 't work, navigation is often broken and always blank screen, it may be caused by damage of the telephone module. find the optical fiber head of telephone module and pull it out, and connect optical fiber loop to cancel the phone function, so that can resume work. The modules connected on a vehicle S.T ring include: CD Changer, Video Display, GPS Navigation, Mobile Phone, Bluetooth, Voice Recognition, Amplifier and Digital/FM/AM Tuner. If you wish to remove one of these modules from the fiber optic ring for repair or fault diagnosis you will require this female (TE) connector / adaptor and fiber optic bypass loop cable to the S.T ring and maintain the integrity of the remaining modules on the ring. It can also be used to diagnose faults by systematically removing modules from the ring and inserting this adapter loop to bypass the module. Core diameter: 1.0 Finished product diameter: 2.3*2 Attenuation: less than 180dB/km Working temperature: -55 C - +85 C Material:plastic colour:black Package Contents: 1 * Male Connector 1 * Female Connector Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.