Apparatus for routing, connecting and terminating fiber optic cables, namely, fiber optic connectors, fiber optic cable connectors, ducting and couplings for organizing and holding fiber optic cables, plastic conduits for fiber optic cables, protective sheaths for fiber optic cables; protective sheaths for fiber optic cables specially adapted to limit the minimum radius below which fiber optic cables should not be bent for reasons of optical and mechanical performance of the fiber optic cables