Bundles up to 3925FT in length (1. 87 in active diameters you specify. Fiber optic cable is a cable containing one or multiple optical fibers that are used to transmit the signal. The optical fiber elements are typically individually coated with layers and contained in a protective tube suitable for the environment where the cable will be deployed. 37 for applications that require lower attenuation. For some applications, some number of optical fibers is bundled together, forming a fiber bundle or fiber-optic bundle. These cables are used mainly for digital audio connections between devices.