Permanent downhole fiber-optic cables are critical infrastructure in wellbore monitoring systems, ensuring reliable transmission of data for applications such as distributed temperature, acoustic, and strain sensing (DTS, DAS, and DSS)—all with one 1/4-in control line. A typical TEF cable is a tube in tube design. The FIMT can contain a range of fibers, both single mode (SMF) and multi mode (MMF). The fiber selection and appropriate filling gels can be customized to meet the customers specifications / requirements. Tensile strength of each wire lies in the ra ge of 270 to 330 KPSI.