Choosing the right fiber size depends on application type, environment (indoor/outdoor), and connector compatibility. They fall into two main categories: Singlemode Fiber (SMF) Multimode Fiber (MMF) 3. Fiber cables also include coating, buffer, and jacket layers, which impact durability, handling, and installation environments. That is why engineers, technicians, and network planners often rely on a fiber optic cable size chart to choose the right. A fiber optic cable is a transmission medium that uses strands of glass or plastic fibers to carry data as pulses of light. It offers high bandwidth, low signal loss, and resistance to electromagnetic interference (EMI), making it ideal for modern high-speed networks.