Indoor fiber optic cable is tight buffer design, usually they consist of the following components inside the cable, the FRP which is non-metallic strengthen member, the tight buffer optical fiber, the Kevlar which is used to further strength the cable structure, making it resist high tension, and the cable outer jacket. The trend is to use LSZH or other compliant PVC materials to make the cable jacket, this will help protect the environment and the health of the end users, this type of cables comes in both singlemode and multimode