For such cables, we recommend using at least a 1. It's important to consider not only the rigidity of the jacket but also the breakout point of the assembly, where the strands exit the jacket and are encased in. The size of conduit you should use depends on the type of fiber optic assembly and the number of cables it will house. For example, our TikTok video below shows a. Premise innerduct is a flexible, non-metallic, corrugated raceway that has long been an essential conduit system for protecting fiber optic cables installed throughout telecommunications spaces and pathways. Then, under Conduit Size, select the size of your conduit and hit "Calculate. Once the fill ratio calculator is computed, the program tells you if it falls within Corning's.