Three main choices are available: cost-effective PVC, LSZH (compliant with regulations), and TPU (for extreme environments). LSZH (Low Smoke Zero Halogen) 3. TPU (Thermoplastic Polyurethane) How to choose ?The main function of the fiber cable outer sheath is to protect the optical fibers in the optical cable from external damage. At the same time, it must have. OCC CABLE JACKET MATERIAL REFERENCE GUIDE The table below is provided as a general reference guide for the properties and typical applications for the common jacket materials used in certain OCC fiber optic cable products. Sheath issues discussed: single jacket versus dual jacket, armored versus unarmored, and metallic versus dielectric. The jacket material determines the reliability, fire resistance, and lifespan of a fiber optic cable.