Fibre optic cable assemblies consist of a group of fibre optic wires gathered together in a protective casing. They are used to transmit data, using total internal refraction of light. The individual strands are often coated with a material such as plastic to prevent the fibre from damage and the assembly may also have a layer of light-absorbing glass between fibres to prevent interference if light leaks from one fibre.
They are often used for long distance telecommunications purposes or for high speed internet connections. They have a greater capacity than other types of electrical cable assemblies.
Fibre optic cable assemblies can differ in the type of fibre used, as well as the configuration of their connectors. Depending on what they are to be used for, they may need to be more rigid or flexible, and the fibres may need to be housed differently. For example, in more hazardous environments the fibres are fitted loosely and helically inside the cable, meaning that when the cable moves the fibres don't have to.